Development of a transport measurement system under multiple extreme conditions

2014 Fiscal Year Final Research Report

• Project/Area Number: 25800198
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Osaka University
• Principal Investigator: KIDA Takanori 大阪大学, 理学(系)研究科(研究院), 助教 (50452412)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 多重極限環境 / パルス強磁場 / 高温超伝導体 / 上部臨界磁場

Outline of Final Research Achievements

We have developed a contactless conductivity measurement apparatus utilizing an rf oscillator based on a proximity detector circuit under high pressure and high magnetic fields. High pressures of up to 6 GPa are generated with a diamond anvil cell (DAC) made of Ni-Cr-Al alloys. High magnetic fields of up to 40 T are generated with a non-destructive pulse magnet. Utilizing this apparatus, we measured the frequency change to determine the upper critical fields (Hc2) of Fe(Te,Se). At ambient pressure, Hc2(T) for H || c was almost linear against T near Tc and was suppressed at low temperatures compared to the conventional one-band Werthamer-Helfand-Hohenberg (WHH) prediction. Under high pressure, suppression of the Hc2(T) at low temperatures became more pronounced. However, we found that the effect of the eddy current heating from the gasket cannot be negligible during field descending process. It is necessary to develop non-metallic gaskets for preventing the Joule's heating.

Free Research Field

強磁場物性