Theory of magnetism-driven negative thermal expansion in inverse perovskite antiferromagnets
Theory of magnetism-driven negative thermal expansion in inverse perovskite antiferromagnets
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DOI：
10.1103/physrevmaterials.3.024407
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发表时间：
2019-02
影响因子：
3.4
通讯作者：
Masaya Kobayashi;M. Mochizuki
中科院分区：
文献类型：
--
作者：
Masaya Kobayashi;M. Mochizuki
Magnetism-induced negative thermal expansion (NTE) observed in inverse perovskite antiferromagnets ${\mathrm{Mn}}_{3}A\mathrm{N}\phantom{\rule{4pt}{0ex}}(A=\mathrm{Zn},\phantom{\rule{0.16em}{0ex}}\mathrm{Ga}$, etc.) is theoretically studied by a classical spin model with competing bond-length-dependent exchange interactions. We numerically reproduce the crystal-volume expansion upon cooling triggered by a noncoplanar antiferromagnetic order and show that the expansion occurs so as to maximize an energy gain of the nearest-neighbor antiferromagnetic interactions. This mechanism is not specific to inverse perovskite magnets and might also be expected in magnets with other crystal structures. We propose other candidate crystal structures that might exhibit NTE through this mechanism.
Magnetism-induced negative thermal expansion (NTE) observed in inverse perovskite antiferromagnets ${\mathrm{Mn}}_{3}A\mathrm{N}\phantom{\rule{4pt}{0ex}}(A=\mathrm{Zn},\phantom{\rule{0.16em}{0ex}}\mathrm{Ga}$, etc.) is theoretically studied by a classical spin model with competing bond-length-dependent exchange interactions. We numerically reproduce the crystal-volume expansion upon cooling triggered by a noncoplanar antiferromagnetic order and show that the expansion occurs so as to maximize an energy gain of the nearest-neighbor antiferromagnetic interactions. This mechanism is not specific to inverse perovskite magnets and might also be expected in magnets with other crystal structures. We propose other candidate crystal structures that might exhibit NTE through this mechanism.