Mn2MnReO6: Synthesis and Magnetic Structure Determination of a New Transition-Metal-Only Double Perovskite Canted Antiferromagnet

详细信息    查看全文

• 作者：Man-Rong Li ; Jason P. Hodges ; Maria Retuerto ; Zheng Deng ; Peter W. Stephens ; Mark C. Croft ; Xiaoyu Deng ; Gabriel Kotliar ; Javier Sánchez-Benítez ; David Walker ; Martha Greenblatt
• 刊名：Chemistry of Materials
• 出版年：2016
• 出版时间：May 10, 2016
• 年：2016
• 卷：28
• 期：9
• 页码：3148-3158
• 全文大小：647K
• 年卷期：0
• ISSN：1520-5002

文摘

Transition-metal-only double perovskite oxides (A₂BB′O₆) are of great interest due to their strong and unusual magnetic interactions; only one compound, Mn₂FeReO₆, was reported in this category to date. Herein, we report the second transition-metal-only double perovskite, Mn₂MnReO₆, prepared at high pressure and temperature. Mn₂MnReO₆ crystallizes in a monoclinic P2₁/n structure, as established by synchrotron X-ray and powder neutron diffraction (PND) methods, with eight-coordinated A sites and rock-salt arrangement of the B and B′-site MnO₆ and ReO₆. Both the structural analysis and the X-ray absorption near edge spectroscopy results indicate mixed valence states of the B/B′-site in Mn²⁺₂Mn^2+/3+Re^5+/6+O₆. The magnetic and PND studies evidence an antiferromagnetic (AFM) transition at ∼110 K and a transition from a simple AFM to canted AFM with net ferromagnetic component at ∼50 K. The observed Efros–Shklovskii variable-range-hopping semiconducting behavior is attributed to the three (A-site Mn²⁺, B-site Mn^2+/3+, and B′-site Re^5+/6+) interpenetrating canted AFM lattices. Theoretical calculations demonstrate that the almost fully polarized Mn states in Mn₂MnReO₆ are driven away from the Fermi level by static on-site interactions and open a small gap, which is responsible for the insulating state in such a d-electron-rich system. These results provide insight of the electronic origin of the physical properties of Mn₂MnReO₆ with local electronic structure similar to that of Mn₂FeReO₆.