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Title: Fluorescence XAS using Ge PAD: Application to High-Temperature Superconducting Thin Film Single Crystals

Abstract

A Ge pixel array detector (PAD) with 100 segments was used in fluorescence x-ray absorption spectroscopy (XAS) study, probing local structure of high temperature superconducting thin film single crystals. Independent monitoring of individual pixel outputs allows real-time inspection of interference of substrates which has long been a major source of systematic error. By optimizing grazing-incidence angle and azimuthal orientation, smooth extended x-ray absorption fine structure (EXAFS) oscillations were obtained, demonstrating that strain effects can be studied using high-quality data for thin film single crystals grown by molecular beam epitaxy (MBE). The results of (La,Sr)2CuO4 thin film single crystals under strain are related to the strain dependence of the critical temperature of superconductivity.

Authors:
;  [1]; ;  [2];  [3]
  1. National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)
  2. NTT Basic Research Laboratories, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)
  3. Universita di Roma 'La Sapienza', P. le Aldo Moro 2, 00185 Rome (Italy)
Publication Date:
OSTI Identifier:
21054773
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 882; Journal Issue: 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644698; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTROSCOPY; CRYSTAL STRUCTURE; CUPRATES; FINE STRUCTURE; FLUORESCENCE; GE SEMICONDUCTOR DETECTORS; HIGH-TC SUPERCONDUCTORS; INCIDENCE ANGLE; LANTHANUM COMPOUNDS; LAYERS; MOLECULAR BEAM EPITAXY; MONOCRYSTALS; STRAINS; STRONTIUM COMPOUNDS; SUBSTRATES; SUPERCONDUCTIVITY; THIN FILMS; X-RAY SPECTRA; X-RAY SPECTROSCOPY

Citation Formats

Oyanagi, H., Zhang, C., Tsukada, A., Naito, M., and Saini, N. L.. Fluorescence XAS using Ge PAD: Application to High-Temperature Superconducting Thin Film Single Crystals. United States: N. p., 2007. Web. doi:10.1063/1.2644698.
Oyanagi, H., Zhang, C., Tsukada, A., Naito, M., & Saini, N. L.. Fluorescence XAS using Ge PAD: Application to High-Temperature Superconducting Thin Film Single Crystals. United States. doi:10.1063/1.2644698.
Oyanagi, H., Zhang, C., Tsukada, A., Naito, M., and Saini, N. L.. Fri . "Fluorescence XAS using Ge PAD: Application to High-Temperature Superconducting Thin Film Single Crystals". United States. doi:10.1063/1.2644698.
@article{osti_21054773,
title = {Fluorescence XAS using Ge PAD: Application to High-Temperature Superconducting Thin Film Single Crystals},
author = {Oyanagi, H. and Zhang, C. and Tsukada, A. and Naito, M. and Saini, N. L.},
abstractNote = {A Ge pixel array detector (PAD) with 100 segments was used in fluorescence x-ray absorption spectroscopy (XAS) study, probing local structure of high temperature superconducting thin film single crystals. Independent monitoring of individual pixel outputs allows real-time inspection of interference of substrates which has long been a major source of systematic error. By optimizing grazing-incidence angle and azimuthal orientation, smooth extended x-ray absorption fine structure (EXAFS) oscillations were obtained, demonstrating that strain effects can be studied using high-quality data for thin film single crystals grown by molecular beam epitaxy (MBE). The results of (La,Sr)2CuO4 thin film single crystals under strain are related to the strain dependence of the critical temperature of superconductivity.},
doi = {10.1063/1.2644698},
journal = {AIP Conference Proceedings},
number = 1,
volume = 882,
place = {United States},
year = {Fri Feb 02 00:00:00 EST 2007},
month = {Fri Feb 02 00:00:00 EST 2007}
}
  • We present the characteristics of superconducting nanowire single photon detectors (SNSPDs) fabricated from amorphous Mo{sub 0.75}Ge{sub 0.25} thin-films. Fabricated devices show a saturation of the internal detection efficiency at temperatures below 1 K, with system dark count rates below 500 cps. Operation in a closed-cycle cryocooler at 2.5 K is possible with system detection efficiencies exceeding 20% for SNSPDs which have not been optimized for high detection efficiency. Jitter is observed to vary between 69 ps at 250 mK and 187 ps at 2.5 K using room temperature amplifiers.
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  • The Al-induced crystallization (AIC) yields a large-grained (111)-oriented Ge thin film on an insulator at temperatures as low as 180 °C. We accelerated the AIC of an amorphous Ge layer (50-nm thickness) by initially doping Ge in Al and by facilitating Ge diffusion into Al. The electron backscatter diffraction measurement demonstrated the simultaneous achievement of large grains over 10 μm and a high (111) orientation fraction of 90% in the polycrystalline Ge layer formed at 180 °C. This result opens up the possibility for developing Ge-based electronic and optical devices fabricated on inexpensive flexible substrates.
  • No abstract prepared.