Giant negative magnetoresistance and kinetic arrest of first-order ferrimagnetic-antiferromagnetic transition in Ge doped Mn2Sb

Abstract

Effect of Ge substitution on first order ferrimagnetic (FRI) -antiferromagnetic (AFM) transition in Mn2Sb has been studied. It shows that transition temperature (Tt) can be tuned between 119 K -271 K by substituting 2.5-10% Ge at Sb site in Mn2Sb. The variation of density of state at Fermi level N(E f ) with Ge substitution shows that dN(E)/dE is positive at E f in the AFM state. With the application of magnetic field Tt shifts to low temperature, which results in a giant negative magnetoresistance (MR) reaching a value of 70% for 2.5% substitution. Our results show that FRI to AFM transformation during cooling stops around 35 K, even though it remains incomplete. It along with non-monotonic variation of lower critical field, open loop in isothermal MR and increasing difference in zero field cooled warming (ZFCW) and field cooled warming (FCW) resistivity with increasing magnetic field shows that FRI to AFM transition is kinetically arrested in the case of 2.5% Ge substitution.

The Nature of Ferromagnetism in a System of Self-Ordered α-FeSi2 Nanorods on a Si(111)-4° Vicinal Surface: Experiment and Theory

“…After obtaining the FORC curves, they were processed using the do FORC software package [ 36 ], in accordance with the formula for ρ ( H a , H b ) reported in [ 33 ]. Subsequently, a square grid was built with different averaging coefficients n (50 and 100) for ρ ( H a , H b ), taking into account the method of numerical estimation of the optimal value of n [ 43 ].…”

“…To this end, a set of 100 magnetization reversal curves were measured in an external field directed along the NRs in a field range of ±1 kOe with a step of 20 Oe. After obtaining a set of experimental curves, the data were processed using the doFORC software package [ 36 ].…”

Chemically Controllable Magnetic Transition Temperature and Magneto‐Elastic Coupling in MnZnSb Compounds

“…MnZnSb is closely related to Mn 2 Sb which crystallizes in the tetragonal space group P 4/ nmm with an anti‐PbFCl structure described by Mn(I) sites arranged in series of 2D square nets with Mn(II) and Sb sites between, or as an NaCl‐like structure, where the atom types alternate in all directions [ 22 ] as shown in Figure a. Ge‐doped Mn 2 Sb has shown a large magnetocaloric effect at the field induced first‐order ferri‐antiferromagnetic transition [ 23 ] and the substitution of the Mn(II) sites by Zn cations have been reported to result in no apparent structural changes [ 22 ] and the stabilization of a pseudo 2D itinerant ferromagnetic ground state with a reduced transition temperature ( T C = 305 K). [ 24 ] The spin‐polarized density of states (DOS) and electronic band structure, with atomic and orbital projection, calculated for MnZnSb using PBE‐GGA (Perdew–Burke–Ernzerhor‐generalized gradient approximation) in a collinear ferromagnetic configuration, are shown in Figure 1b,c respectively.…”

Magnetoelastic transition and giant anisotropic magnetostriction effect in textured Mn<sub>1.9</sub>Co<sub>0.1</sub>Sb polycrystal

“…2017年, Guo等人 [11] 在多晶的反钙钛矿 . 正分的Mn 2 Sb不会发生一级磁相变, 但是 通过过渡族元素取代Mn位 [14][15][16][17][18][19][20][21][22][23] 或主族元素取代Sb 位 [24][25][26][27] , 合金在低温下出现反铁磁态, 导致发生亚铁磁 到反铁磁的一级磁弹性相变, 相变附近伴随有晶格常 数a和c的各向异性突变, 但晶体的对称性保持不变.…”

“…方向平行和垂直. 从图中可以明显看到, Mn 1.9 Co 0.1 Sb合 金在低温区域呈现出反铁磁态[14][15][16][17][18][19][20][21][22][23][24][25][26][27] , 但仔细观察发现 在低温反铁磁区域合金的磁化强度并不为零, 这是少图 1 (网络版彩图)室温下Mn 1.9 Co 0.1 Sb合金的精修粉末 XRD衍射图谱 Figure 1 (Color online) Rietveld refinement of powder XRD pattern recorded at room temperature for Mn 1.9 Co 0.1 Sb alloy. 图 2 (网络版彩图)室温下对Mn 1.9 Co 0.1 Sb合金粉末以及铸 锭表面和断面测得的XRD衍射图谱.…”