Strong interplay between structure and magnetism in the giant magnetocaloric intermetallic compound LaFe11.4Si1.6:: a neutron diffraction study

被引：75

作者：

Wang, FW ^{[1
]}

Wang, GJ

Hu, FX

Kurbakov, A

Shen, BG

Cheng, ZH

机构：

[1] CEA, CNRS, Lab Leon Brillouin, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France

[2] Chinese Acad Sci, Inst Phys, State Key Lab Magnetism, Beijing 10080, Peoples R China

[3] Russian Acad Sci, Petersburg Nucl Phys Inst, Gatchina 188300, Russia

来源：

JOURNAL OF PHYSICS-CONDENSED MATTER | 2003年 / 15卷 / 30期

关键词：

D O I：

10.1088/0953-8984/15/30/309

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

Crystallographic and magnetic structures of the cubic NaZn13-type intermetallic compound LaFe11.4Si1.6 have been studied by means of powder neutron diffraction. Rietveld analysis indicates that Si atoms substitute for Fe atoms randomly on two different Fe sites. All spins in the unit cell are aligned ferromagnetically with the Fe-I (8b) moment smaller than the Fe-II (96i) one. The long-range ferromagnetic ordering induces a drastic expansion of the lattice and the coexistence of the large and small volume phases near the Curie temperature. Even in the ferromagnetic state, the lattice expansion still correlates strongly with the spontaneous magnetic moment, marked by a large positive magnetovolume coupling constant kC = 1.14 x 10(-8) cm(6) emu(-2). From the temperature dependence of Fe-Fe bond lengths, we suggest that the Fe-Fe exchange interaction between the clusters (each formed by a central Fe-I atom and 12 surrounding Fell atoms) plays an important role in the magnetic properties of La(Fe1-xAl/Si-x)(13), as does that within the clusters.

引用

页码：5269 / 5278

页数：10

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