A new high pressure phase of MnTiO3 and its magnetic property
A new high pressure phase of MnTiO3 and its magnetic property
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DOI：
10.1016/0022-3697(69)90234-0
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发表时间：
1969-07
影响因子：
4
通讯作者：
Y. Syono;S. Akimoto;Y. Ishikawa;Y. Endoh
中科院分区：
文献类型：
--
作者：
Y. Syono;S. Akimoto;Y. Ishikawa;Y. Endoh
在高温高压条件下合成了一种新的高压相MnTiO 3 II.大气压下的MnTiO 3 I相和MnTiO 3 II相的平衡相界为P（kb）= 110 - 0.044 T（℃）。粉末样品的X射线分析表明，高压相MnTiO 3 II具有无序的钛铁矿结构，其六方晶格参数为a= 5.2051 <$，c= 13.699 <$，ca = 2.632和V= 321.4 <$[3]。从MnTiO 31到MnTiO 3 II的转变使a轴膨胀1.3%，c轴收缩4.1%，体积减小1.6%.穆斯堡尔效应和顺磁ESR测量均表明MnTiO 3 II在24°±1° K以下是反铁磁的.磁化率几乎在Néel温度以下服从Curie-Weiss定律，在低于TN时稍偏离Curie-Weiss定律，这与MnTiO 3 I形成鲜明对比。提出Mn 2+离子的共价性对锰钛铁矿的磁相互作用和晶体稳定性都起重要作用的可能性。
A high pressure phase of MnTiO 3 II is newly synthesized at high pressures and temperatures. An equilibrium phase boundary between an atmospheric pressure phase of MnTiO 3 I and MnTiO 3 II is P (kb)= 110− 0.044 T (° C). X-ray analysis of powder specimens has revealed that the high pressure phase MnTiO 3 II has the disordered ilmenite structure with the hexagonal lattice parameters of a= 5.2051 Å, c= 13.699 Å, c a= 2.632 and V= 321.4 Å [3]. The transformation from MnTiO 3 1 to MnTiO 3 II causes an expansion of the a axis by 1.3 per cent and a contraction of the c axis by 4.1 per cent, resulting a volume decrease of 1.6 per cent. Both Mössbauer effect and paramagnetic ESR measurements suggest that MnTiO 3 II is antiferromagnetic below 24°±1° K. The magnetic susceptibility obeys the Curie-Weiss law almost down to the Néel temperature and slightly deviates from it below T N, in marked contrast with that of MnTiO 3 I. A possibility that the covalency of Mn 2+ ions plays an important role both in the magnetic interactions and the crystal stability of manganese ilmenites is suggested.