Large superconducting Fe Se crystals of(001) orientation have been prepared via a hydrothermal ion release/introduction route for the first time. The hydrothermally derived Fe Se crystals are up to 10 mm×5 mm...Large superconducting Fe Se crystals of(001) orientation have been prepared via a hydrothermal ion release/introduction route for the first time. The hydrothermally derived Fe Se crystals are up to 10 mm×5 mm×0.3 mm in dimension. The pure tetragonal FeSe phase has been confirmed by x-ray diffraction(XRD) and the composition determined by both inductively coupled plasma atomic emission spectroscopy(ICP-AES) and energy dispersive x-ray spectroscopy(EDX). The superconducting transition of the Fe Se samples has been characterized by magnetic and transport measurements. The zero-temperature upper critical field H(c2) is calculated to be 13.2–16.7 T from a two-band model. The normal-state cooperative paramagnetism is found to be predominated by strong spin frustrations below the characteristic temperature T(sn), where the Ising spin nematicity has been discerned in the FeSe superconductor crystals as reported elsewhere.展开更多
This paper presents a new fabrication process for the SOI-based novel miniature electric field sensor. This new process uses polyimide film to release the SiO_2 layer.Compared with the CO_2 critical point release meth...This paper presents a new fabrication process for the SOI-based novel miniature electric field sensor. This new process uses polyimide film to release the SiO_2 layer.Compared with the CO_2 critical point release method,it significantly improves the device surface cleanliness and shortens the process flow.The impurity on the base layer is analyzed.The problem of peak and butterfly-type contamination occurring on the base layer of the SOI wafer during the DRIE process is discussed and solved by thickening the photoresist layer and coating with polyimide film twice.This new process could fabricate MEMS sensors and actuators such as SOI-based electric field sensors,gyroscopes,and micro mirrors and can be an alternative fabrication process compared to commercial SOIMUMPS fabrication processes.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574370,11274358,and 11190020)the National Basic Research Program of China(Grant No.2013CB921700)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB07020100)
文摘Large superconducting Fe Se crystals of(001) orientation have been prepared via a hydrothermal ion release/introduction route for the first time. The hydrothermally derived Fe Se crystals are up to 10 mm×5 mm×0.3 mm in dimension. The pure tetragonal FeSe phase has been confirmed by x-ray diffraction(XRD) and the composition determined by both inductively coupled plasma atomic emission spectroscopy(ICP-AES) and energy dispersive x-ray spectroscopy(EDX). The superconducting transition of the Fe Se samples has been characterized by magnetic and transport measurements. The zero-temperature upper critical field H(c2) is calculated to be 13.2–16.7 T from a two-band model. The normal-state cooperative paramagnetism is found to be predominated by strong spin frustrations below the characteristic temperature T(sn), where the Ising spin nematicity has been discerned in the FeSe superconductor crystals as reported elsewhere.
基金supported by the National High Technology Research and Development Program of China(No.2011AA040405)the National Natural Science Foundation of China(Nos.61101049,61201078)
文摘This paper presents a new fabrication process for the SOI-based novel miniature electric field sensor. This new process uses polyimide film to release the SiO_2 layer.Compared with the CO_2 critical point release method,it significantly improves the device surface cleanliness and shortens the process flow.The impurity on the base layer is analyzed.The problem of peak and butterfly-type contamination occurring on the base layer of the SOI wafer during the DRIE process is discussed and solved by thickening the photoresist layer and coating with polyimide film twice.This new process could fabricate MEMS sensors and actuators such as SOI-based electric field sensors,gyroscopes,and micro mirrors and can be an alternative fabrication process compared to commercial SOIMUMPS fabrication processes.