O presente trabalho, realizado junto ao Grupo de Novos Materiais e Dispositivos (GNMD), no Laboratório de Microeletrônica do Departamento de Sistemas Eletrônicos da Escola Politécnica da USP, visou determinar algumas das propriedades termo-mecânicas de materiais depositados pela técnica de plasma enhanced chemical vapor deposition (PECVD) que são importantes para o desenvolvimento de sistemas microeletromecânicos (MEMS). O módulo de elasticidade, a tensão mecânica residual, o coeficiente de expansão térmica e a condutividade térmica de filmes finos de carbeto de silício amorfo hidrogenado (a-SiC:H) e de oxinitreto de silício (SiOxNy) foram estudados. Medidas de nanoindentação e ressonância de cantilevers foram utilizadas para a obtenção do módulo de elasticidade e os resultados obtidos foram similares (75 e 91 GPa) pelos dois métodos e compatíveis com valores encontrados na literatura. Além disso, obteve-se o módulo de elasticidade de filmes de cromo (285 GPa). A tensão mecânica residual dos filmes utilizados neste trabalho foi medida através da curvatura do substrato induzida pela deposição dos filmes e pela deformação de cantilevers. O valor médio da tensão mecânica, obtido pela curvatura do substrato, variou de -69 MPa até -1750 MPa, mostrando grande dependência das condições de deposição dos filmes. O método que utiliza a deformação de cantilevers possibilitou a obtenção do gradiente de tensão mecânica, que também mostrou uma dependência das condições de deposição, sendo sempre o a-SiC:H quase estequiométrico o menos tensionado. O coeficiente de expansão térmica foi medido utilizando a técnica do gradiente de temperatura e o valor obtido foi similar a valores reportados na literatura para o carbeto de silício cristalino. Para um a-SiC:H quase estequiométrico foi obtido um coeficiente de expansão térmica de 3,41 m/oC, enquanto para um a-SiC:H rico em carbono o valor foi de 4,36 m/oC. Também foi verificado que a variação da resistência do cromo em função da temperatura é pequena, não permitindo sua utilização como sensor de temperatura e inviabilizando a obtenção da condutividade térmica dos filmes estudados. Além disso, foram apresentados trabalhos promissores, mostrando o potencial dos materiais estudados para o desenvolvimento de MEMS. Nesses trabalhos, demonstrou-se a viabilidade de integrar microestruturas atuadas termicamente e guias de onda ópticos, utilizando os materiais estudados neste trabalho. Foram fabricados chaves ópticas, portas lógicas ópticas, fontes de luz integradas e acoplamento das fontes de luz com guias de onda. / This work, realized at the New Materials and Devices Group (GNMD) at the Microelectronics Laboratory of the Department of Electronic Systems of the Polytechnic School of the University of São Paulo, focused at the determination of thermo-mechanical properties of materials deposited by plasma enhanced chemical vapor deposition (PECVD) that are important for the development of microelectromechanical systems (MEMS). The Youngs modulus, the residual stress, the coefficient of thermal expansion and the thermal conductivity of amorphous hydrogenated silicon carbide (a-SiC:H) and silicon oxynitride (SiOxNy) thin films were studied. Nanoindentation and the resonance of cantilevers were used to obtain the Youngs modulus. The results were similar (75 and 91 GPa) with both methods and compatible with literature values. Further, the Youngs modulus of chromium films was also obtained (285 GPa). The residual stress of thin films was obtained through the substrate curvature induced by the film deposition and through the deformation of cantilever beams. The residual stress, obtained through the substrate curvature, varied between -69 MPa and -1750 MPa, showing great dependence on the deposition conditions of these materials. The deformation of cantilevers allowed the determination of the stress gradient and it was also affected by the deposition conditions. In all stress measurements the near stoichiometry a-SiC:H film was less stressed. The coefficient of thermal expansion was measured using the temperature gradient technique and the obtain values were similar to those reported in the literature for crystalline silicon carbide. For a near stoichiometry a-SiC:H film, a value of 3.41 m/oC was obtained, while a carbon rich film showed a thermal expansion coefficient of 4.36 m/oC. It was also verified that the variation of the chromium resistance as a function of temperature is small. This did not allow the utilization of chromium as a temperature sensor, which prevented the obtention of the thermal conductivity of the studied films. Also, some promising works were presented, showing potential applications of the studied materials for the development of MEMS. In these works, the viability of integration of thermal actuated microstructures and optical waveguides was demonstrated. In these works, optical switches, optical logic gates, integrated light sources and coupling of integrated light sources with optical waveguides were presented.

Ultra cold quantum gas is a convenient system to study fundamental questions of modern physics, such as phase transitions and critical phenomena. This master thesis is devoted to experimental investigation of the thermodynamics susceptibilities, such as the isothermal compressibility and the thermal expansion coefficient of a trapped Bose-Einstein condensate (BEC) of 87Rb atoms. The critical phenomena and the critical exponents across the transition can explain the behavior of the isothermal compressibility and the thermal expansion coefficient near the critical temperature TC. By employing the developed formalism of global thermodynamics variables, we carry out a statistical treatment of Bose gas in a 3D harmonic potential. After that, comparison of obtained results reveals the most appropriate state variables describing the system, namely volume and pressure parameter V and Π respectively. The both are related with the confining frequencies and BEC density distribution. We apply this approach to define the set of new thermodynamic variables of BEC, and also to construct the isobaric phase diagram V T. Its allows us to extract the compressibility κT and the thermal expansion coefficient βΠ. The behavior of the isothermal compressibility corresponds to the second-order phase transition, while the thermal expansion coefficient around the critical point behaves as β ∼ tr-α, where tr is reduced temperature of the system and α is the critical exponent on the basic of these. Results we have obtained the critical exponent α = 0.15±0.09, which allows us to determine the system dimensionality by means of the scaling theory, relating the critical exponents with the dimensionality. As a result, we found out that the dimensionality of the system to be d ∼ 3, one is in agreement with the real dimension of the system. / Amostras atômicas ultrafrias de um gás de Bose são convenientes para estudar questões fundamentais da física moderna, como as transições de fase e fenômenos críticos em condensados de Bose-Einstein (BEC). A minha dissertação dedica se à investigação das susceptibilidades termodinâmicas como a compressibilidade isotérmica e o coeficiente de expansão térmica de a traves da transição de um BEC de 87Rb. Os fenômenos críticos e os exponentes críticos a traves da transição podem explicar o comportamento da compressibilidade isotérmica e do coeficiente de expansão térmica perto da temperatura crítica TC. Ao empregar o desenvolvido formalismo das variáveis termodinâmicas globais, levamos a cabo o tratamento estatístico de um gás de Bose num potencial harmônico 3D. Depois da comparação dos resultados obtidos, revelam as mais apropriadas variáveis de estado descrevendo o sistema, chamadas parâmetro de volume e pressão, V e Π respectivamente. As duas estão relacionadas com as frequências de confinamento e a distribuição de densidade do BEC. Nós aplicamos esta abordagem para definir um conjunto de novas variáveis termodinâmicas do BEC, e também para construir o diagrama de fase isobárico V T. O anterior nós permite extrair a compressibilidade κT e o coeficiente de expansão termina βΠ. O comportamento da compressibilidade isotérmica corresponde a uma transição de fase de segunda ordem enquanto que o coeficiente de expansão térmica ao redor do ponto crítico comporta se como β ∼ tr-α, onde tr é a temperatura reduzida do sistema, e α o exponente crítico. Deste resultado nós obtemos um exponente critico, α = 0.15 ± 0.09, que permite determinar a dimensionalidade do sistema a traves da teoria de escala, relacionando os exponentes críticos com a dimensionalidade. Como resultado, encontramos que a dimensionalidade do sistema é d ∼ 3 que está de acordo como a dimensão real do sistema.

Ultra cold quantum gas is a convenient system to study fundamental questions of modern physics, such as phase transitions and critical phenomena. This master thesis is devoted to experimental investigation of the thermodynamics susceptibilities, such as the isothermal compressibility and the thermal expansion coefficient of a trapped Bose-Einstein condensate (BEC) of 87Rb atoms. The critical phenomena and the critical exponents across the transition can explain the behavior of the isothermal compressibility and the thermal expansion coefficient near the critical temperature TC. By employing the developed formalism of global thermodynamics variables, we carry out a statistical treatment of Bose gas in a 3D harmonic potential. After that, comparison of obtained results reveals the most appropriate state variables describing the system, namely volume and pressure parameter V and Π respectively. The both are related with the confining frequencies and BEC density distribution. We apply this approach to define the set of new thermodynamic variables of BEC, and also to construct the isobaric phase diagram V T. Its allows us to extract the compressibility κT and the thermal expansion coefficient βΠ. The behavior of the isothermal compressibility corresponds to the second-order phase transition, while the thermal expansion coefficient around the critical point behaves as β ∼ tr-α, where tr is reduced temperature of the system and α is the critical exponent on the basic of these. Results we have obtained the critical exponent α = 0.15±0.09, which allows us to determine the system dimensionality by means of the scaling theory, relating the critical exponents with the dimensionality. As a result, we found out that the dimensionality of the system to be d ∼ 3, one is in agreement with the real dimension of the system. / Amostras atômicas ultrafrias de um gás de Bose são convenientes para estudar questões fundamentais da física moderna, como as transições de fase e fenômenos críticos em condensados de Bose-Einstein (BEC). A minha dissertação dedica se à investigação das susceptibilidades termodinâmicas como a compressibilidade isotérmica e o coeficiente de expansão térmica de a traves da transição de um BEC de 87Rb. Os fenômenos críticos e os exponentes críticos a traves da transição podem explicar o comportamento da compressibilidade isotérmica e do coeficiente de expansão térmica perto da temperatura crítica TC. Ao empregar o desenvolvido formalismo das variáveis termodinâmicas globais, levamos a cabo o tratamento estatístico de um gás de Bose num potencial harmônico 3D. Depois da comparação dos resultados obtidos, revelam as mais apropriadas variáveis de estado descrevendo o sistema, chamadas parâmetro de volume e pressão, V e Π respectivamente. As duas estão relacionadas com as frequências de confinamento e a distribuição de densidade do BEC. Nós aplicamos esta abordagem para definir um conjunto de novas variáveis termodinâmicas do BEC, e também para construir o diagrama de fase isobárico V T. O anterior nós permite extrair a compressibilidade κT e o coeficiente de expansão termina βΠ. O comportamento da compressibilidade isotérmica corresponde a uma transição de fase de segunda ordem enquanto que o coeficiente de expansão térmica ao redor do ponto crítico comporta se como β ∼ tr-α, onde tr é a temperatura reduzida do sistema, e α o exponente crítico. Deste resultado nós obtemos um exponente critico, α = 0.15 ± 0.09, que permite determinar a dimensionalidade do sistema a traves da teoria de escala, relacionando os exponentes críticos com a dimensionalidade. Como resultado, encontramos que a dimensionalidade do sistema é d ∼ 3 que está de acordo como a dimensão real do sistema.

No description available.

L’utilisation croissante de systèmes électroniques miniaturisés induit une forte demande en microsources d’énergie performantes, telles que les microbatteries au lithium. En vue d’améliorer les propriétés de l’électrolyte, nous avons étudié les propriétés électriques et thermomécaniques d’électrolytes solides de type borate de lithium. Une corrélation entre la conductivité ionique et le coefficient de dilatation thermique (CTE) a été mise en évidence pour différentes compositions de verres massifs. A partir des résultats de CTE obtenus, un modèle de prédiction basé sur les travaux de Appen permettant la détermination de ce dernier en fonction de la composition chimique a été développé. Dans un second temps, différentes techniques de préparation de cibles denses nitrurées ont été mises en œuvre afin d’abaisser le CTE de la cible et ainsi permettre son utilisation sur une plus longue durée. Par ailleurs, l’utilisation d’une cible nitrurée a également été envisagée pour augmenter la teneur en azote dans les couches minces. Finalement, des couches minces d’électrolyte de différentes compositions ont été préparées par pulvérisation cathodique (sous plasma d’argon ou d’azote pur) et ont fait l’objet d’une caractérisation chimique, structurale, électrique et thermomécanique. Le rôle bénéfique de l’azote sur la conductivité ionique des couches minces a ainsi pu être confirmé. / The growing use of miniaturized electronic devices results in a strong demand in high-performance energy microsources, such as lithium microbatteries. In order to improve electrolyte properties, we have studied the electrical and thermomechanical properties of bulk electrolyte based on lithium borate glasses. A correlation between ionic conductivity and thermal expansion coefficient has been evidenced for bulk materials. Further to CTE results, a predicting model based on studies leaded by Appen allowing a determination of CTE as a function of the chemical composition has been developed. In a second time, different preparation techniques of dense nitrated targets have been implemented in order to decrease their CTE and to allow their use for a longer period. Otherwise, nitrated targets have also been considered to increase the nitrogen content in thin films. Finally, electrolyte thin films of different compositions have been prepared by rf magnetron sputtering (under pure argon or nitrogen gas) and have been chemically, structurally, electrically and thermomecanically characterized. The favorable influence of nitrogen on the ionic conductivity of thin films has been confirmed.

O presente trabalho, realizado junto ao Grupo de Novos Materiais e Dispositivos (GNMD), no Laboratório de Microeletrônica do Departamento de Sistemas Eletrônicos da Escola Politécnica da USP, visou determinar algumas das propriedades termo-mecânicas de materiais depositados pela técnica de plasma enhanced chemical vapor deposition (PECVD) que são importantes para o desenvolvimento de sistemas microeletromecânicos (MEMS). O módulo de elasticidade, a tensão mecânica residual, o coeficiente de expansão térmica e a condutividade térmica de filmes finos de carbeto de silício amorfo hidrogenado (a-SiC:H) e de oxinitreto de silício (SiOxNy) foram estudados. Medidas de nanoindentação e ressonância de cantilevers foram utilizadas para a obtenção do módulo de elasticidade e os resultados obtidos foram similares (75 e 91 GPa) pelos dois métodos e compatíveis com valores encontrados na literatura. Além disso, obteve-se o módulo de elasticidade de filmes de cromo (285 GPa). A tensão mecânica residual dos filmes utilizados neste trabalho foi medida através da curvatura do substrato induzida pela deposição dos filmes e pela deformação de cantilevers. O valor médio da tensão mecânica, obtido pela curvatura do substrato, variou de -69 MPa até -1750 MPa, mostrando grande dependência das condições de deposição dos filmes. O método que utiliza a deformação de cantilevers possibilitou a obtenção do gradiente de tensão mecânica, que também mostrou uma dependência das condições de deposição, sendo sempre o a-SiC:H quase estequiométrico o menos tensionado. O coeficiente de expansão térmica foi medido utilizando a técnica do gradiente de temperatura e o valor obtido foi similar a valores reportados na literatura para o carbeto de silício cristalino. Para um a-SiC:H quase estequiométrico foi obtido um coeficiente de expansão térmica de 3,41 m/oC, enquanto para um a-SiC:H rico em carbono o valor foi de 4,36 m/oC. Também foi verificado que a variação da resistência do cromo em função da temperatura é pequena, não permitindo sua utilização como sensor de temperatura e inviabilizando a obtenção da condutividade térmica dos filmes estudados. Além disso, foram apresentados trabalhos promissores, mostrando o potencial dos materiais estudados para o desenvolvimento de MEMS. Nesses trabalhos, demonstrou-se a viabilidade de integrar microestruturas atuadas termicamente e guias de onda ópticos, utilizando os materiais estudados neste trabalho. Foram fabricados chaves ópticas, portas lógicas ópticas, fontes de luz integradas e acoplamento das fontes de luz com guias de onda. / This work, realized at the New Materials and Devices Group (GNMD) at the Microelectronics Laboratory of the Department of Electronic Systems of the Polytechnic School of the University of São Paulo, focused at the determination of thermo-mechanical properties of materials deposited by plasma enhanced chemical vapor deposition (PECVD) that are important for the development of microelectromechanical systems (MEMS). The Youngs modulus, the residual stress, the coefficient of thermal expansion and the thermal conductivity of amorphous hydrogenated silicon carbide (a-SiC:H) and silicon oxynitride (SiOxNy) thin films were studied. Nanoindentation and the resonance of cantilevers were used to obtain the Youngs modulus. The results were similar (75 and 91 GPa) with both methods and compatible with literature values. Further, the Youngs modulus of chromium films was also obtained (285 GPa). The residual stress of thin films was obtained through the substrate curvature induced by the film deposition and through the deformation of cantilever beams. The residual stress, obtained through the substrate curvature, varied between -69 MPa and -1750 MPa, showing great dependence on the deposition conditions of these materials. The deformation of cantilevers allowed the determination of the stress gradient and it was also affected by the deposition conditions. In all stress measurements the near stoichiometry a-SiC:H film was less stressed. The coefficient of thermal expansion was measured using the temperature gradient technique and the obtain values were similar to those reported in the literature for crystalline silicon carbide. For a near stoichiometry a-SiC:H film, a value of 3.41 m/oC was obtained, while a carbon rich film showed a thermal expansion coefficient of 4.36 m/oC. It was also verified that the variation of the chromium resistance as a function of temperature is small. This did not allow the utilization of chromium as a temperature sensor, which prevented the obtention of the thermal conductivity of the studied films. Also, some promising works were presented, showing potential applications of the studied materials for the development of MEMS. In these works, the viability of integration of thermal actuated microstructures and optical waveguides was demonstrated. In these works, optical switches, optical logic gates, integrated light sources and coupling of integrated light sources with optical waveguides were presented.

Actuellement, la qualité de l’imagerie provenant de systèmes optiques spatiaux est limitée par la taille de leurs miroirs et la masse des structures supportant le miroir. Le développement de systèmes athermiques légers (un seul matériau) constitue le principal challenge dans l’amélioration de ces systèmes. De matériaux légers, résistants mécaniquement (E/ρ3 > 10, σf > 100 MPa) et stables thermiquement (< 2,0.e-6/K) doivent être développés. Dans ce cadre, notre travail porte sur l’élaboration de composites céramiques associant un matériau à coefficient de dilatation thermique (CTE) positif résistant mécaniquement (alumine ou zircone cériée) et un matériau à CTE très négatif (tungstate de zirconium ou β-eucryptite). L'étude du tungstate de zirconium a révélé plusieurs problèmes de décomposition et de réactions avec certaines matrices oxydes, menant à l’abandon de cet oxyde dans l’élaboration des composites. Dans le cas de la β-eucryptite, un phénomène de vermiculation a été mis en évidence, conduisant à la formation d’une porosité intragranulaire. L’optimisation des paramètres de frittage a permis de limiter cette porosité. L’étude du comportement thermique de la β-eucryptite confirme que son CTE très négatif provient principalement d’un phénomène de fissuration, généré par l’anisotropie de dilatation de sa maille cristalline. Cette fissuration est dépendante de la taille des grains mais également de la taille des agrégats de grains dans le cas des poudres. Ainsi, bien que le CTE intrinsèque de la β-eucryptite soit très faible (-0,4.e-6/K), son CTE extrinsèque peut atteindre des valeurs jusqu'à -10,9.e-6/K selon les conditions d’élaboration. Dans ce travail, deux stratégies d’élaboration de composites sont étudiées. Le premier cas consiste à diminuer le CTE des matrices oxydes à partir d’une poudre de β-eucryptite non microfissurée (-0,4.e-6/K) tandis que le second cas consiste à obtenir des matériaux à CTE très faible à partir d’une poudre de β-eucryptite microfissurée (-3,0.e-6/K). Lors de l’utilisation de la matrice en zircone cériée, le taux de dopage au cérium est optimisé afin de limiter la transformation de phase de la zircone. Cette transformation, induite par les contraintes de tension exercées par la β-eucryptite, affecte la linéarité du comportement thermique du composite. Dans les deux cas d’étude, les composites denses montrent une modification du CTE intrinsèque de la β-eucryptite passant de -0,4.e-6/K à plus de +3,2.e-6/K en raison des contraintes de compression appliquées par la matrice (alumine ou zircone cériée). La relaxation de ces contraintes nécessite une sous-densification des composites. A partir de ces observations, différents composites à CTE très faible sont élaborés. Toutefois, le sous-frittage des composites associé à la microfissuration de la β-eucryptite diminuent fortement les propriétés mécaniques des matériaux ainsi élaborés. / High resolution satellite imagery from space optical systems is mainly limited by the mirror size and the mass of structures supporting the mirror. Nowadays, the development of light athermal systems is the major challenge to improve these optical systems. So, light materials having good mechanical properties (E/ρ3 > 10, σf > 100 MPa) and thermal stability (< 2.0e-6/K) are required. Within this context, our project consists in processing new ceramic composites by combining positive thermal expansion coefficient (TEC) materials having good mechanical properties (alumina or ceria doped zirconia) and negative TEC materials (zirconium tungstate or β-eucryptite) The processing of zirconium tungstate-based materials showed several decomposition and chemical reactions with some oxide matrix leading to its giving up. In the case of β-eucryptite, vermicular phenomenon occurs during sintering leading to the formation of intragranular porosity. Sintering parameters optimization can limit this porosity. The study of the thermal behavior of pure β-eucryptite materials shows that the very negative TEC results from microcracking, generated by the TEC anisotropy of its crystal lattice. This microcracking depends on the grain size and the aggregate size in the case of powder materials. Despite the fact that the TEC of its lattice (called intrinsic TE C equals to -0.4e-6/K) is very low, its bulk (or extrinsic) TEC can reach values until -10.9e-6/K according to the processing conditions. In this work, two strategies for developing composites were studied. The first one consists in decreasing the matrix TEC using an uncracked β-eucryptite powder (-0.4e-6/K) while the second one consists in elaborating near zero TEC materials from a microcracked β-eucryptite powder (-3.0e-6/K). When ceria-doped zirconia is used, ceria content must be adjusted in order to limit zirconia phase transformation. This transformation is driven by tensile stresses induced by the β-eucryptite and modifies the composite thermal behavior linearity. In both studied cases, dense composites show a modification of the β-eucryptite intrinsic TEC from -0.4e-6/K to more than +3.2e-6/K as a consequence of compressive stresses applied by the oxide matrix. An uncompleted densification of composites is required to relax these stresses. Taking into account these observations, several very low TEC composites were elaborated. However, the uncompleted densification of composites and the β-eucryptite microcracking greatly decrease the mechanical properties of these materials.

Cieľom predkladanej diplomovej práce je skúmať a analyzovať možnosti prispôsobovania koeficientu tepelnej rozťažnosti nástrekov z kompozitných materiálov deponovaných na substráty pomocou technológie cold spray. Kompozitné materiály sú v tomto prípade reprezentované zmiešanými práškami, ktoré sú pripravené pridávaním fázy s negatívnou tepelnou rozťažnosťou do základného materiálu s kladným koeficientom tepelnej rozťažnosti. Takto pripravené nástreky môžu byť užitočné pri opravovaní a renovácii strojárenských súčiastok. V prvej časti je priblížená samotná technológia cold spray spolu s jej využitím pri opravách a renováciách v strojárenskom priemysle. Ďalej sa práca zaoberá tepelnou rozťažnosťou materiálov, kde je predstavený jav negatívnej tepelnej rozťažnosti. V experimentálnej časti práce je vyhodnotený potenciálny efekt negatívnej tepelnej rozťažnosti pri deponovaní nástrekov pomocou technológie cold spray.

No description available.

Increasing interest in an effciency enhancement of existing energy sources led to an extended research in the field of thermoelectrics. Especially skutterudites with their high power factor (electric conductivity times Seebeck coefficient squared) are suitable thermoelectric materials. However, a further improvement of their thermoelectric properties is necessary. The relatively high thermal conductivity can be decreased by introducing loosely bound guest ions, whereas atom substitution or nanostructuring (as thin films) could yield an increased power factor. The present work proves the feasibility to deposit single phase skutterudite thin films by MBE technique. In this regard CoSby and FeSby film series were deposited with three different methods: i) codeposition at elevated temperatures, ii) codeposition at room temperature followed by post-annealing, and iii) modulated elemental reactant method. The structural and thermoelectric properties of these films were investigated by taking the thermal stability of the film and the substrate properties into account. Compared to the stoichiometric Sb content of skutterudites of 75 at.%, a small excess of Sb is necessary for achieving single phase skutterudite films. It was found, that the deposited single phase CoSb3 films reveal bipolar conduction (and therefore a low Seebeck coefficient), whereas FeSb3 films show p-type conduction and very promising power factors at room temperature. The need of substrates with a low thermal conductivity and a suitable thermal expansion coefficient is also demonstrated. A high thermal conductivity influences the measurements of the Seebeck coefficient and the obtained values will be underestimated by thermal shortening of the film by the substrate. If the thermal expansion coefficient of film and substrate differ strongly from each other, crack formation at the film surface was observed. Furthermore, the realization of controlled doping by substitution as well as the incorporation of guest ions was successfully shown. Hence, this work is a good starting point for designing skutterudite based thin film structures. Two successful examples for such structures are given: i) a thickness series, where a strong decrease of the resistivity was observed for films with a thickness lower than 10nm, and ii) a FexCo1-xSb3 gradient film, for which the gradient was maintained even at an annealing temperature of 400°C.