Interplay between the Crystalline and Magnetic Structures in Lightly Cr-Doped Bi0.37Ca0.63Mn0.96Cr0.04O2.99

详细信息    查看全文

• 作者：Chun-Chuen Yang ; Wen-Hsien Li ; Chun-Ming Wu ; Carissa H. C. Li ; Jirong Sun ; Jeffrey W. Lynn
• 刊名：Inorganic Chemistry
• 出版年：2010
• 出版时间：April 5, 2010
• 年：2010
• 卷：49
• 期：7
• 页码：3297-3304
• 全文大小：1099K
• 年卷期：v.49,no.7(April 5, 2010)
• ISSN：1520-510X

文摘

The interplay between the crystalline and magnetic structures of a 4% Cr-doped Bi_0.37Ca_0.63Mn_0.96Cr_0.04O_2.99 has been investigated by alternating current (ac) magnetic susceptibility, electrical resistivity, and neutron diffraction measurements. The compound crystallizes into a monoclinic P2₁/m symmetry. A Jahn−Teller distortion occurs at 280 K. The thermal behavior of charge transport may be described by a three-dimensional variable range hopping conduction. Strong interplay between the localized magnetic electrons and the itinerant electrons are clearly revealed as the localization length increases by 20% when the Mn spins become ordered below 85 K. Short range magnetic correlations persist up to 160 K. The collinear magnetic structure can be viewed as consisting of ferromagnetic spin-trimers antiferromagnetically embedded in a ferromagnetic environment. Cr-doping reduces the charge ordering temperature and the magnetic ordering temperature. It nevertheless introduces long-range ferromagnetism.