@article{oai:muroran-it.repo.nii.ac.jp:00006662, author = {SUN, Peijie and NAKANISHI, Yoshiki and NAKAMURA, Mitsuteru and YOSHIZAWA, Masahito and OHASHI, Masashi and 巨海, 玄道 and OOMI, Gendo and 関根, ちひろ and SEKINE, Chihiro and 城谷, 一民 and SHIROTANI, Ichimin}, issue = {5}, journal = {Physical review. Third series. B, Condensed matter and materials physics}, month = {Feb}, note = {application/pdf, The filled skutterudite compound SmRu4P12 undergoes a complex evolution from a paramagnetic metal (phase I) to a probable multipolar ordering insulator (phase II) at TMI~16.5 K, then to a magnetically ordered phase (phase III) at TN~14 K. Elastic properties under hydrostatic pressures were investigated to study the nature of the ordering phases. We found that distinct elastic softening above TMI is induced by pressure, giving evidence of quadrupole degeneracy of the ground state in the crystalline electric field. It also suggests that quadrupole moment may be one of the order parameters below TMI. Strangely, the largest degree of softening is found in the transverse elastic constant CT at around 0.5-0.6 GPa, presumably having relevance to the competing and very different Gruneisen parameters Ω of TMI and TN. The interplay between the two phase transitions is also verified by the rapid increase of TMI under pressure with a considerably large Ω of 9. These results can be understood on the basis of the proposed octupole scenario for SmRu4P12}, pages = {054114-1--054114-7}, title = {Anomalous elastic softening of SmRu4P12 under high pressure}, volume = {75}, year = {2007}, yomi = {オオミ, ゲンドウ and セキネ, チヒロ and シロタニ, イチミン} }