Lattice-driven magnetic transitions in Al(Fe,T)2X2 compounds

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:481

Article

Lejeune, B. T.^1,3  Jensen, B. A.⁴  Barua, R.¹  Stonkevitch, E.¹  McCallum, R. W.⁵  Kramer, M. J.⁴  Lewis, L. H.^1,2,3 

[1] Northeastern Univ, Dept Chem Engn, Boston, MA 02115 USA

[2] Northeastern Univ, Dept Mech & Ind Engn, Boston, MA 02115 USA

[3] Northeastern Univ, George J Kostas Res Inst Homeland Secur, Burlington, MA 01803 USA

[4] US DOE, Div Mat Sci & Engn, Ames Lab, Ames, IA USA

[5] McCallum Consulting LLC, Santa Fe, NM USA

关键词: Magnetic materials;    Metals;    Magnetocaloric;    AlFe2B2;    Rare-earth-free;   

DOI  :  10.1016/j.jmmm.2019.03.026

来源: Elsevier

【 摘 要 】

Systematic trends connect detailed composition, lattice parameters and magnetic transition temperatures in the ferromagnetic intermetallic compound AlT2X2 with the Mn2AlB2-type crystal structure, where T = Mn, Fe, Ni, Co and X = B, C. Data were derived from both literature reports and from experiments performed on synthesized samples (T = (Fe1-xNix)(2), x = 0, 0.05, 0.1; X = (B0.9C0.1)(2)). It is observed that compositional variation alters specific bonds responsible for the magnetic phase transition response, which ranges from 200 K <= T-t <= 310 K. Elemental composition that provides changes in the c-axis length and the associated (T-T)(c-axis) interatomic distance contribute the largest bonding effects to magnetic phase transition temperature T-t, alterations. Overall, these results are attributed to the dependence of T-t on the specifics of the Fe sublattice occupancy, electronic state and T-T bonding. In contrast, T-t is found to be largely independent of the (b/a) axial ratios and the associated (T-X)(b-axis)/(T-X)((ac)-plane) interatomic distance ratios, indicating that interatomic interactions along the a-axis have little effect on the T-t.

【 授权许可】

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