Yamato Y, Matsukawa M, Nimori S, Suryanarayanan R, Murano Y, Nakanishi Y, Apostu M, Revcolevschi A, Koyama K, Kobayashi N
Department of Materials Science and Technology, Iwate University, Morioka 020-8551, Japan.
J Phys Condens Matter. 2009 Dec 2;21(48):486001. doi: 10.1088/0953-8984/21/48/486001. Epub 2009 Oct 30.
We have studied the effect of pressure on the anomalous lattice striction, both in the ab-plane and along the c-axis, of (La,Pr)(1.2)Sr(1.8)Mn(2)O(7) single crystals over the temperature region where the paramagnetic insulator to ferromagnetic metal transition takes place. We have examined the temperature dependence of the resistivity and the magnetization under applied pressure. The chemical pressure effect due to Pr-substitution at the La site suppresses the transition temperature of the parent crystal, while the application of external pressure on Pr-substituted crystals enhances the double exchange driven metallic state, resulting in a stable rise of T(c).
我们研究了压力对(La,Pr)(1.2)Sr(1.8)Mn(2)O(7)单晶在顺磁绝缘体到铁磁金属转变发生的温度范围内，在ab平面和沿c轴方向上反常晶格收缩的影响。我们研究了施加压力下电阻率和磁化强度的温度依赖性。由于在La位点用Pr替代而产生的化学压力效应抑制了母晶体的转变温度，而对Pr替代晶体施加外部压力则增强了双交换驱动的金属态，导致Tc稳定上升。
