Li Run-Wei, Belik Alexei A, Wang Zhi-Hong, Shen Bao-Gen
Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, Zhejiang 315201, People's Republic of China.
J Phys Condens Matter. 2009 Feb 18;21(7):076002. doi: 10.1088/0953-8984/21/7/076002. Epub 2009 Jan 23.
Magnetization, resistivity, and specific heat were studied systematically in the absence and presence of magnetic field in Pr(0.7)Pb(0.3)MnO(3) single crystals, in which electronic phase separation occurs near the ferromagnetic/metallic-paramagnetic/insulating phase transition and the metal-insulator transition temperature is much higher than the Curie temperature. These measurements allow us to extract some fundamental physical parameters such as Fermi energy, density of states at the Fermi energy, Debye temperature, and interaction among electrons, phonons, and magnons. Furthermore, the magnetic entropy was studied around the phase transition temperature regime. It was found that a magnetic entropy change associated with the transition from the connected ferromagnetic phase to isolated superparamagnetic clusters appeared near the metal-insulator transition temperature following a large magnetic entropy change near the ferromagnetic-paramagnetic phase transition.
在Pr(0.7)Pb(0.3)MnO(3)单晶中，系统研究了在无磁场和有磁场情况下的磁化强度、电阻率和比热。在该单晶中，电子相分离发生在铁磁/金属-顺磁/绝缘相变附近，且金属-绝缘体转变温度远高于居里温度。这些测量使我们能够提取一些基本物理参数，如费米能、费米能处的态密度、德拜温度以及电子、声子和磁振子之间的相互作用。此外，还研究了相变温度区域附近的磁熵。结果发现，在金属-绝缘体转变温度附近，出现了与从连通铁磁相到孤立超顺磁团簇转变相关的磁熵变化，该变化出现在铁磁-顺磁相变附近的大磁熵变化之后。
