溶融Cuをフラックスとして得た新しい層状化合物PrRh_<4.8>B_2単結晶の化学状態及び性質

概要

論文の詳細を見る
A new layer structure compound PrRh_<4.8>B_2 was obtained by a molten metal flux growth method, using Cu as a flux. This compound belongs to the orthorhombic system with the spaee group Fmmm. Lattice parameters were a=0.9697(4)nm, b=0.5577(2)nm and c=2.564(3)nm. The structure of the compound is of a modified CeCo_3B_2-type, which is explained by a stacking model of Pr-B and rhodium layers. X-ray photoelectron spectra were taken under three conditions : (i) surface of fractured in the vacuum of the spectrometer ; (ii) surface exposed to air after fracture in the spectrometer ; and, (iii) surface fractured in air. The X-ray photoelectron spectroscopic study and electron probe micro-analysis results show that a few monolayers of Cu atoms exist between the crystals of PrRh_<4.8>B_2. The thermo-gravimetric curve shows that oxidation of the PrRh_<4.8>B_2 proceeds above 873 K. Weight gain of the specimen heated up to 1473 K in air is 13.44%. Sample forms PrBO_3 and Rh as a result of the oxidation. The temperahre dependcnce of the inverse static magnetic susceptibility x^<-1> obeys the Curie-Weiss law at temperatures above 50 K. The magnetic moment μ_<eff> is 4.2 μ_B and the Curie-Weiss temperature Θ_p is - 13 K. The value of micro Vickers hardness for c-plane with the orthorhombic symmetry of PrRh_<4.8>B_2 is 6.7±0.6 GPa.
社団法人日本セラミックス協会の論文
1999-11-01