Elastic and Magnetic Properties of Bilayer Manganites : La_<2-2x>Sr_<1+2x>Mn_2O_7 for x = 0.35 and 0.40

概要

論文の詳細を見る
We have grown single crystals of LSMO(327) for x = 0.35 and x = 0.40 and investigated the elastic properties systematically, together with the electrical resistivity, magnetoresistance and magnetization. Elastic anomaly around the magnetic transition temperature T_c, at which remarkable metal-insulator transition occurs, has been found in the longitudinal as well as shear elastic constants for x = 0.35 and 0.40. They all exhibit a dip around T_c and a remarkable hardening below T_c implying strong couplings between magnetic moments and elastic strains. Furthermore, it was found that the amount of the elastic softening of C_<33> and C_<66> become smaller with increasing x, which implies that the ration of dγ polarization, d(3z^2 - r^2)/d(x^2 - y^2) is decreasing with increasing x. We will discuss obtained results in terms of the 3d electric state of Mn ions in connection with a degree of carrier concentration, dγ-band width and crystalline electric field (CEF) effect.
社団法人日本物理学会の論文
2002-08-15