(Sr-Ca)RuO_3系の遍歴電子磁性 -インバー効果- Itinerant Electron Magnetism of (Sr-Ca)RuO_3 System -Invar Effect-
We report here the results of Debye-Scherrer X-ray diffraction measurements in the temperature range from 12K to 300K of the perovskite compounds SrRuO<SUB>3</SUB> and CaRuO<SUB>3</SUB>. We show that SrRuO<SUB>3</SUB> indicates an clear anomaly with the temperature dependence of the unit-cell parameters and volume below its ferromagnetic transition temperature T<SUB>c</SUB> of 160K through magnetovolume effect. In particular, the volume of SrRuO<SUB>3</SUB> is almost constant below T<SUB>c</SUB>, and invar effect is discovered for the first time in transition-metal oxide, which is seen in 3d transition-metal itinerant magnets, e.g., Fe-Ni alloy. Therefore, it is concluded that SrRuO<SUB>3</SUB> is classified to a moderately weak itinerant ferromagnet. On the other hand, CaRuO<SUB>3</SUB> shows no anomaly in the variation of the volume with temperature, suggesting that magnetic ordering does not occur in this compound.
粉体および粉末冶金 43(9), 1090-1094, 1996-09-15
Japan Society of Powder and Powder Metallurgy