11 |
Aplicação da espectroscopia de correlação angular perturbada na investigação de interações hiperfinas em compostos de háfnio, indio e cádmio com os ligantes Fsup(1-), OHsup(1-) e EDTA / Application of the perturbed angular correlation in the investigation of hyperfine interactions in compounds of hafnium, indium and cadmium with Fsup(1-), OHsup(1-) and EDTA ligandsAMARAL, ANTONIO A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:00Z (GMT). No. of bitstreams: 0 / O presente trabalho realiza a investigação dos parâmetros hiperfinos, incluindo a sua natureza dinâmica, em compostos ligantes em solução a temperatura ambiente (295 K) e resfriada (77K) através da espectroscopia de Correlação Angular γγ Perturbada (CAP). Para a realização das medidas experimentais, utilizou-se núcleos de prova radioativos de 111In111Cd, 181Hf181Ta e 111mCd111Cd, que decaem através de cascata gama. As amostras foram preparadas diluindo-se soluções com os núcleos radioativos em água, quando se investigou a interação do núcleo de prova com o ligante água; adicionando-se soluções com os núcleos radioativos em solução tampão, quando se investigou a interação do núcleo de prova com os íons ligantes provenientes do próprio tampão (CO32- e HCO31-) e com o OH1-; e adicionando-se soluções com os núcleos radioativos em soluções do ligante ácido etilenodiaminotetracético (EDTA), este em pH entre 4,0 e 5,0, (que corresponde ao pH da própria solução saturada do EDTA) e em solução tampão de pH entre 9 e 10. Assim foi possível investigar os efeitos gerados por cada um desses métodos de preparação de amostras nas medidas CAP. Finalmente foi feita uma análise comparativa para os vários métodos de inserção dos núcleos de prova na amostra, considerando-se aspectos químicos e nucleares. A inexistência de medidas para esse tipo de amostra, justifica a importância dos resultados obtidos. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
|
12 |
Junction tuning by ferroelectric switching in silicon nanowire Schottky-barrier field effect transistorsSessi, V., Mulaosmanovic, H., Hentschel, R., Pregl, S., Mikolajick, T., Weber, W. M. 07 December 2021 (has links)
We report on a novel silicon nanowire-based field effect transistor with integrated ferroelectric gate oxide. The concept allows tuning the carrier transport in a non-volatile approach by switching the polarization in the ferroelectric layer close to the source Schottky-junction. We interpret the results in terms of tuning the transmissibility of the Schottky-junction for charge carriers. The experimental results provide a first step towards the integration of memory-in-logic concepts with reconfigurable nanowire transistors.
|
13 |
Material perspectives of HfO₂-based ferroelectric films for device applicationsToriumi, Akira, Xu, Lun, Mori, Yuki, Tian, Xuan, Lomenzo, Patrick D., Mulaosmanovic, Halid, Materano, Monica, Mikolajick, Thomas, Schroeder, Uwe 20 June 2022 (has links)
Ferroelectric HfO₂ attracts a huge amount of attention not only for memory and negative capacitance, but also for programmable logic including memory-in-logic and neuromorphic applications. However, the understanding of material fundamentals still needs to be improved. This paper gives material fundamentals and new insights to this ferroelectric material for future device applications. In particular, the key role of dopants, effects of the interface on the ferroelectric phase, and a detailed discussion of the switching kinetics are of central focus. Based on material properties newly obtained, we discuss opportunities of ferroelectric HfO₂ for device applications.
|
14 |
Next Generation Ferroelectric Memories enabled by Hafnium OxideMikolajick, T., Schroeder, U., Lomenzo, P. D., Breyer, E. T., Mulaosmanovic, H., Hoffmann, M., Mittmann, T., Mehmood, F., Max, B., Slesazeck, S. 22 June 2022 (has links)
Ferroelectrics are theoretically an ideal solution for low write power nonvolatile memories. However, the complexity of ferroelectric perovskites has hindered the scaling of such devices to competitive feature sizes. The discovery of ferroelectricity in hafnium oxide solved this issue. Ferroelectric memories in three variants, capacitor based ferroelectric RAM, ferroelectric field effect transistors and ferroelectric tunneling junctions have become competitors for future memory solutions again. In this paper, the basics and current status of hafnium oxide based ferroelectric memory devices is described and recent results are shown.
|
15 |
Deconvoluting charge trapping and nucleation interplay in FeFETs: Kinetics and ReliabilityPesic, Milan, Padovani, Andrea, Slesazeck, Stefan, Mikolajick, Thomas, Larcher, Luca 07 December 2021 (has links)
Discovery of ferroelectric (FE) behavior in HfO 2 removed the compatibility roadblocks between the state-of-the-art CMOS and FE memories. Even though FE FETs (FeFETs) are scaled into 22 nm nodes and beyond, the limits of the technology as well as the physical mechanisms and reliability are still under research. In this paper we successfully developed a multiscale modeling platform to understand the interplay between the FE switching and charge trapping. Starting from the nucleation theory and rigorous charge transport modeling we present for the first time a self-consistent modeling framework we used for investigation of reliability and variability in FeFETs.
|
16 |
Variants of Ferroelectric Hafnium Oxide based Nonvolatile MemoriesMikolajick, T., Mulaosmanovic, H., Hoffmann, M., Max, B., Mittmann, T., Schroeder, U., Slesazeck, S. 26 January 2022 (has links)
Ferroelectricity is very attractive for nonvolatile memories since it allows non-volatility paired with a field driven switching mechanism enabling a very low-power write operation. Non-volatile memories based on ferroelectric lead-zirconium-titanate (PZT) (see fig. la) are available on the market for more than a quarter of a century now [1]. Yet they are limited to niche applications due to the compatibility issues of the ferroelectric material with CMOS processes and the associated limited scalability [2]. The discovery of ferroelectricity in doped hafnium oxide has revived the activities towards a variety of scalable ferroelectric nonvolatile memory devices
|
Page generated in 0.0586 seconds