J. Mater. Sci. Technol. ›› 2021, Vol. 68: 103-111.DOI: 10.1016/j.jmst.2020.08.002

• Research Article • Previous Articles     Next Articles

First-principles investigation of B2 partial disordered structure, martensitic transformation, elastic and magnetic properties of all-d-metal Ni-Mn-Ti Heusler alloys

Ziqi Guana, Jing Baia,b,d,*(), Jianglong Guc, Xinzeng Lianga, Die Liua,b, Xinjun Jianga,b, Runkai Huanga,b, Yudong Zhange, Claude Eslinge, Xiang Zhaoa, Liang Zuoa,**()   

  1. a Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang 110819, China
    b School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China
    c State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China
    d Hebei Provincial Laboratory for Dielectric and Electrolyte Functional Materials, Qinhuangdao 066004, China
    e Laboratoire d'Étude des Microstructures et de Mécanique des Matériaux, LEM3, CNRS, UMR 7239, University of Lorraine, 57045 Metz, France
  • Received:2020-04-05 Revised:2020-05-28 Accepted:2020-06-27 Published:2021-03-30 Online:2021-05-01
  • Contact: Jing Bai,Liang Zuo
  • About author:**lzuo@mail.neu.edu.cn (L. Zuo).
    *Key Laboratory for Anisotropy and Texture of Materi-als, Northeastern University, Shenyang 110819, China.E-mail addresses: baijing@neuq.edu.cn (J. Bai),

Abstract:

In this work, the B2 partial disordered structure of the austenitic parent phase, martensitic transformation, elastic and magnetic properties of the Ni8Mn4+xTi4-x (x = 0, 1 and 2) Heusler alloys have been systematically investigated by the first-principles calculations. The preferential atomic occupation of B2 structure is one Ti atom exchange with the nearest neighboring Mn atom from the view of lowest energy principle. This disordered exchange sites (Mn-Ti) and the excess Mn atoms occupying the Ti sites (MnTi) could reduce the nearest Mn-Mn distance, resulting in the antiferromagnetic state in the austenitic and martensitic phases of the alloys. The total magnetic moment of the alloy decreases with the increasing Mn content; it is ascribed to the antiferromagnetic magnetic moments of the excess Mn atoms. When x = 0, the alloy does not undergo martensitic transformation since the austenite has absolute phase stability. The martensitic transformation will occur during cooling process for x = 1 or 2, owing to the energy difference between the austenite and the martensite could provide the driving force for the phase transformation. The elastic properties of the cubic austenitic phase for the Ni2MnTi alloy is calculated, and the results reveal the reason why Ni-Mn-Ti alloy has excellent mechanical properties. The origin of martensitic transformation and magnetic properties was discussed based on the electronic density of states.

Key words: Ni-Mn-Ti, First-principles calculations, Martensitic transformation, B2 partial disordered structure, Elastic properties