Atomic Order Along the Half‐ to Full‐Heusler Transition in Ni1+xMnSb. Issue 5 (24th September 2021)

• Record Type: Journal Article
• Authors: Neibecker, Pascal; Xu, Xiao; Simonne, David; Hollender, Lucas; Porcher, Florence; Senyshyn, Anatoliy; Omori, Toshihiro; Kainuma, Ryosuke; Petry, Winfried; Leitner, Michael
• Other Names: Eckern Ulrich guestEditor.; Gegenwart Philipp guestEditor.
• Is Part Of: Physica status solidi. Volume 259:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-24
• Subjects: constitutional vacancies -- half-Heusler -- neutron diffraction -- NiMnSb; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.202100174
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract : Structural voids are a defining feature of the half‐Heusler structure. Using temperature‐dependent neutron diffraction, complemented by room‐temperature X‐ray diffraction and high‐resolution neutron diffraction as well as calorimetry and macroscopic magnetization measurements, the disordering of these vacancies is followed across the Clb –L21 transition in samples of Ni 1 + x MnSb for various Ni excesses x . The thermal vacancy concentration increases toward high temperatures, and excess vacancy concentrations large enough to increase the low‐temperature macroscopic magnetization can be retained by quenching. Finally, the consequences of the strongly differing relaxation rates of order and vacancy concentrations are demonstrated, showing that in these and related systems the thermal history potentially determines material properties such as ordering temperatures much more strongly than usually. Abstract : The half‐Heusler C1b structure is defined by the characteristic order of structural voids. Temperature‐dependent neutron diffraction in the pseudobinary Ni1+ x MnSb phase diagram elucidates the entropy‐driven transition to L21 order and uncovers the slow relaxation of thermal vacancy concentrations.