Perovskite-Structure TlMnO3: A New Manganite with New Properties

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• 作者：Wei Yi ; Yu Kumagai ; Nicola A. Spaldin ; Yoshitaka Matsushita ; Akira Sato ; Igor A. Presniakov ; Alexey V. Sobolev ; Yana S. Glazkova ; Alexei A. Belik
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：September 15, 2014
• 年：2014
• 卷：53
• 期：18
• 页码：9800-9808
• 全文大小：572K
• ISSN：1520-510X

文摘

We synthesize a new member of the AMnO₃ perovskite manganite family (where A is a trivalent cation)鈥攖hallium manganite, TlMnO₃鈥攗nder high-pressure (6 GPa) and high-temperature (1500 K) conditions and show that the structural and magnetic properties are distinct from those of all other AMnO₃ manganites. The crystal structure of TlMnO₃ is solved and refined using single-crystal X-ray diffraction data. We obtain a triclinically distorted structure with space group P1虆 (No. 2), Z = 4, and lattice parameters a = 5.4248(2) 脜, b = 7.9403(2) 脜, c = 5.28650(10) 脜, 伪 = 87.8200(10)掳, 尾 = 86.9440(10)掳, and 纬 = 89.3130(10)掳 at 293 K. There are four crystallographic Mn sites in TlMnO₃ forming two groups based on the degree of their Jahn鈥揟eller distortions. Physical properties of insulating TlMnO₃ are investigated with M枚ssbauer spectroscopy and resistivity, specific heat, and magnetization measurements. The orbital ordering, which persists to the decomposition temperature of 820 K, suggests A-type antiferromagnetic ordering with the ferromagnetic planes along the [鈭?01] direction, consistent with the measured collinear antiferromagnetism below the N茅el temperature of 92 K. Hybrid density functional calculations are consistent with the experimentally identified structure, insulating ground state, and suggested magnetism, and show that the low symmetry originates from the strongly Jahn鈥揟eller distorted Mn³⁺ ions combined with the strong covalency of the Tl³⁺鈥揙 bonds.