||福谷 克之 教授
||Metal-insulator transition in hydrogenated RNiO3
|| It is known that some of perovskite nickelates RNiO3 with rare earths as R exhibits a metal-insulator transition (MIT) due to temperature changes , and there are many materials in which physical properties such as magnetism and electric conductivity change due to hydrogen doping [2, 3]. Recent studies have suggested that doping RNiO3 with hydrogen induces a new insulating state, and it has been reported that the resistance of SmNiO3(SNO) changes significantly at room temperature due to hydrogen doping . However, the mechanism of hydrogen-induced MIT is not well understood.
The purpose of my research is to elucidate the mechanism of hydrogen-induced MIT in RNiO3 by experimentally measuring the relation between the hydrogen concentration and electronic structure.
In the present study, we prepared RNiO3(R=Sm, Nd, La) thin films on a substrate, and measured the changes in the electric resistance of the sample due to hydrogenation. We also measured the hydrogen concentration in the sample by using nuclear reaction analysis(NRA). We discuss the MIT mechanism due to hydrogenation.
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