Revealing the nature of magnetic phases in the semi-Heusler alloy Cu0.85Ni0.15MnSb

Abstract

We report the magnetic, magnetocaloric, and magnetotransport properties of the semiHeusler alloy Cu 0.85 Ni 0.15 MnSb, which exhibits coexistence of antiferromagnetic (AFM) and ferromagnetic (FM) phases. A broad magnetic phase transition is evident from the temperature variations of magnetization, heat capacity, and isothermal magnetic entropy change. This is due to the presence of both AFM and FM phases at low temperatures. The variation of electrical resistivity with temperature shows three distinct regions of magnetic phases. The magnetoresistance (MR) results also show the presence of AFM and FM phases at temperatures below 45 K, and a FM phase at temperature above 45K. Though there is no signature of a spin-glass state at low temperatures, various results point towards the presence of short-range magnetic correlations at low temperatures.

About the Role of Fe-Ions in the Formation of Magnetocaloric Effect in Ho(Co1-xFex)2Compounds

“…1) it can be argued that the phase transition in these compounds is a second order one. For the calculation of isothermal entropy change(∆S), which can be made using formulae (1) [12,13], the samples magnetization eld dependencies in the external magnetic elds (07) T in the wide temperature range with a step of 510 K were performed…”

“…The inset II shows the values of ∆T FWHM for R(M 1−x Fe x ) 2 compounds, where M = Co or Ni. Data have been taken from the papers [9][10][11][12]15] and from the present stady. The gure shows that for all R(M 1−x Fe x ) 2 compounds with low Ni or Co substitutions by Fe, a signicant increase of ∆S(T ) peak width is observed.…”

“…Because of the absence of data on the temperature dependences of heat capacity for the DC magnetic eld of 0.5 T, the calculation of ∆T calc was performed using the value of C P,H under µ 0 H = 0 (inset Fig. 3 To give more detailed magnetocaloric characteristics of the studied compounds, a comparison of their relative cooling capacity (RCP) [12] with the RCP of the similar compound was made:…”

“…Authors [12], investigating structure and magnetothermal properties of the Tb(Co 1−x Fe x ) 2 system also found a signicant magnetic entropy temperature range broadening in the * corresponding author; e-mail: maksim.anikin@urfu.ru TbCo 0.9 Fe 0.1 compound compared with that in TbCo 2 . The neutron diraction studies carried out in wide temperature range indicated existence of the structural phase transition (from rhombohedral to cubic with decreasing temperature) associated with the magnetic phase transition and broadening of the transition temperature interval when Fe is added.…”

Nature of electron correlation and hybridization in NixCu1−xMnSb Heusler alloys

“…On the other hand, it is well established from electrical transport measurements on Ni x Cu 1−x MnSb that the conductivity/metallicity increases with decreasing temperature. 7,23 Thus, the C1 and C2 satellites may be related to charge transfer between Mn 3d and metallic conduction bands at the Fermi level. Similar temperature dependent satellite structures have also been observed in Mn 2p spectra of manganites 14 as well as 2p spectra of other TMs 24 and ruthenates 25 and have been attributed to charge transfer between valence 3d states and the conduction band.…”