Role of the electronic structure in the morphotropic phase boundary of TbxDy1−xCo2 studied by first-principle calculation

Abstract

Physically parallel to ferroelectric morphotropic phase boundary, a phase boundary separating two ferromagnetic phases of different crystallographic symmetries was experimentally found in TbxDy1−xCo2 via high-resolution synchrotron X-ray diffraction. However, lack of the theoretical support makes the morphotropic phase boundary in ferromagnetic system debatable. Here, a first-principle calculation was employed to investigate the electronic structure variation during the morphotropic phase transition in TbxDy1−xCo2. It offers a theoretical basis for the ferromagnetic phase of different crystallographic symmetries in TbxDy1−xCo2. It also provides an explanation for why morphotropic phase boundary occurs in TbxDy1−xCo2 alloys and offers a serviceable method to search for the morphotropic phase boundary phenomena in other alloys via computational rather than experimental method.