2019年3月13日，课题组一篇论文“Sign-changed-magnetostriction effect of morphotropic phase boundary in pseudobinary DyCo2-DyFe2 Laves compounds"被美国APS刊物Physcial Review Materials录用。

论文摘要：

Morphotropic phase boundary (MPB) has recently attracted considerable interest in a number of pseudobinary RT₂ (R is rare earth; T is 3d-transition metal) Laves phase compounds to achieving enhanced large magnetostriction or near zero magnetostriction. Unlike the MPBs separating a tetragonal and a rhombohedral phase in the literatures, here we report that in the DyCo₂-DyFe₂ system, ferromagnetic MPB separating two tetragonal phases of differed tetragonality can also lead to sign-changed-magnetostriction effect. Synchrotron x-ray diffraction data demonstrate the coexistence of two tetragonal phases in the broadening MPB regime, one with c/a < 1 (T1 phase) and the other one with c/a > 1 (T2 phase). The preferable domain switches of T1 phase with weaker magnetocrystalline anisotropy under low fields and the subsequent domain switches of T2 phase with stronger magnetocrystalline anisotropy under high fields give rise to the sign-changed-magnetostriction effect. Further analysis suggests that the MPB effect on magnetostrictive response is determined by the intrinsic magnetostriction, the magnetocrystalline anisotropy as well as the magnetic ordering of two end terminals that form the MPB. This work reveals a new type MPB in pseudobinary RT₂ compounds and provides an effective recipe for designing sign-tunable magnetostrictive materials.