On the electronic origin of the inverse magnetocaloric effect in Ni–Co–Mn–In Heusler alloys
On the electronic origin of the inverse magnetocaloric effect in Ni–Co–Mn–In Heusler alloys
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DOI：
10.1088/0022-3727/43/5/055004
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
A. N. Vasiliev;O. Heczko;Olga S. Volkova;T. Vasilchikova;T. Voloshok;K. Klimov;W. Ito;R. Kainuma;K. Ishida;K. Oikawa;S. Fähler
中科院分区：
文献类型：
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作者：
A. N. Vasiliev;O. Heczko;Olga S. Volkova;T. Vasilchikova;T. Voloshok;K. Klimov;W. Ito;R. Kainuma;K. Ishida;K. Oikawa;S. Fähler
为了了解在 Ni-Co-Mn-In 系统中观察到的逆磁热效应的电子起源，我们结合使用了磁化强度、电阻率和比热等间接实验探针。研究结果与同结构霍斯勒合金（例如 Ni-Mn-Ga）的能带结构进行了比较。我们认为 Ni-Co-Mn-In 中的逆磁热效应源于接近费米能的高态密度。在奥氏体状态内，这会导致铁磁带分裂。马氏体的结构变化提供了一种在较低温度下降低高态密度的替代方法，这种方法不需要能带分裂，因此不支持铁磁有序。
In order to understand the electronic origin of the inverse magnetocaloric effect observed in a Ni–Co–Mn–In system we used a combination of indirect experimental probes as magnetization, resistivity and specific heat. The findings are compared with the band structure of isostructural Heusler alloys such as Ni–Mn–Ga. We suggest that the inverse magnetocaloric effect in Ni–Co–Mn–In originates from the high density of states close to Fermi energy. Within the austenite state this causes ferromagnetic band splitting. The structural change to the martensite allows an alternative way to reduce the high density of states at lower temperatures, which does not require band splitting and thus does not support ferromagnetic order.