Pressure effect on magnetic transition temperature and magnetic phase diagram of Mn2−xCoxSb

Abstract

Pressure effects on spin-flop transition temperature (Tsf) of Mn2−xCoxSb have been measured in order to study the nature of spin-flop phase transitions. The magnetic phase diagrams for Tsf versus concentration and for Tsf versus pressure have been determined. Tsf increases with increasing applied pressure (dTsf/dp=2.9 K/kbar for x=0.05, dTsf/dp=3.7 K/kbar for x=0.10, dTsf/dp=3.3 K/kbar for x=0.15, and dTsf/dp=2.7 K/kbar for x=0.20). On the other hand, Tsf decreases slowly with x up to ≂0.05 and increases rapidly under further increasing x at normal atmospheric pressure. On the basis of these results, the microscopic origin of the magnetic anisotropy of Mn2−xCoxSb is discussed.

Magnetic and Magnetocaloric Properties in Ferrimagnetic Mn2−xCoxSb ($x=0.15$ and 0.20) Alloys

“…The lattice parameters a and c and the corresponding unit cell volume V and c/a relation for these alloys are listed in Table I. should also be noticed, all of which are consistent with the former measurements [10,23]. In addition, the decrease of c/a and the increase of V as well as the converse changes of a and c suggest an anisotropic deformation of crystal lattice in Co-introduced Mn 2 Sb alloys.…”

“…According to the earlier results, the stoichiometric Mn 2 Sb alloy crystallizes in a tetragonal Cu 2 Sb-type structure with P4/nmm space group [7][8][9][10], which orders FRI state below T N ~550 K [7][8][9][10]. There exist two crystallographically nonequivalent sites of Mn atoms, generally referred as Mn(I) and Mn(II) with magnetic moments 2.1µ B and 3.9µ B [7][8][9][10], respectively, which have an antiparallel alignment each other.…”

“…According to the earlier results, the stoichiometric Mn 2 Sb alloy crystallizes in a tetragonal Cu 2 Sb-type structure with P4/nmm space group [7][8][9][10], which orders FRI state below T N ~550 K [7][8][9][10]. There exist two crystallographically nonequivalent sites of Mn atoms, generally referred as Mn(I) and Mn(II) with magnetic moments 2.1µ B and 3.9µ B [7][8][9][10], respectively, which have an antiparallel alignment each other. The structure of pure Mn 2 Sb alloy presents a natural stacking of Mn(II)-2Mn(I)-Mn(II) triple layers repeatedly along the tetragonal c-axis [7][8][9][10], in which the FRI structure forms due to the parallel alignment of the triple layer to each other, while the AFM state appears when the triple layer aligns antiparallelly to each other [7][8][9][10].…”

“…There exist two crystallographically nonequivalent sites of Mn atoms, generally referred as Mn(I) and Mn(II) with magnetic moments 2.1µ B and 3.9µ B [7][8][9][10], respectively, which have an antiparallel alignment each other. The structure of pure Mn 2 Sb alloy presents a natural stacking of Mn(II)-2Mn(I)-Mn(II) triple layers repeatedly along the tetragonal c-axis [7][8][9][10], in which the FRI structure forms due to the parallel alignment of the triple layer to each other, while the AFM state appears when the triple layer aligns antiparallelly to each other [7][8][9][10]. It has been reported that the substituted Mn 2 Sb-based alloys by various elements (V, Cr, Co, Cu) for Mn as well as (In, Sn) for Sb reveal a FOMT from the FRI to AFM state with the decreasing temperature [7,[11][12][13][14][15][16].…”

“…There has been considerable interest in these compounds due to the large change of unit cell volume, resistivity, and magnetization, which therefore give rise to the large MCE, magnetoresistance, and magnetostriction effect [7,[11][12][13][14][15][16]. However, in spite of various studies on the doped Mn 2 Sb-based compounds there are still very less investigations on the FOMTs, especially the related functional properties, for Co-modified Mn 2 Sb-based alloys [10,[17][18][19][20][21]. In this paper, the Co-doped Mn 2 Sb alloys with the small amount of Co content are prepared and the structure and transitional behaviors are studied.…”