We have investigated electron transport characteristics of a hydrogen-deficient dihydride of yttrium YH2-3 (-0.3 < & δ < 0.05) focusing particularly on the effect of hydrogen deficiency on carrier relaxation time. At room- and low-temperatures, dc-specific resistivities obtained from electrical measurements show minimum values when hydrogen-deficient quantity δ is approximately -0.1. Optical conductivities were obtained from reflectance measurements by the Kramers-Knonig transformation. When & is changed, the carrier scattering rate determined from the optical conductivity shows a behavior similar to those of dc resistivities. Not only the carrier scattering rate but also a band-gap energy E0 associated with a Γ2-Γ25 transition is influenced by the hydrogen deficiency; E0 shows a maximum value as δ is about -0.1. Hall coefficients are found to be positive but fairly small (∼10-11 m3/C), indicating that electrons as well as holes presumably contribute to electric conduction in YH2+δ.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版ステータス||Published - 2004 2|
ASJC Scopus subject areas
- Physics and Astronomy(all)