This work reports on the electronic, magnetic, and structural properties of the binary intermetallic compounds ${\mathrm{Mn}}_{3\ensuremath{-}x}\mathrm{Ga}$. The tetragonal ${\mathrm{DO}}_{22}$ phase of the ${\mathrm{Mn}}_{3\ensuremath{-}x}\mathrm{Ga}$ series, with $x$ varying from 0 to 1.0 in steps of $x=0.1$, was successfully synthesized and investigated. It was found that all these materials are hard magnetic, with energy products ranging from $10.1\phantom{\rule{0.3em}{0ex}}\mathrm{kJ}\phantom{\rule{0.2em}{0ex}}{\mathrm{m}}^{\ensuremath{-}3}$ for low Mn content $(x\ensuremath{\rightarrow}1)$ to $61.6\phantom{\rule{0.3em}{0ex}}\mathrm{kJ}\phantom{\rule{0.2em}{0ex}}{\mathrm{m}}^{\ensuremath{-}3}$ for high Mn content $(x\ensuremath{\rightarrow}0)$. With decreasing Mn content, the average saturation magnetization per atom increases from $0.26{\ensuremath{\mu}}_{B}$ for ${\mathrm{Mn}}_{3}\mathrm{Ga}$ to $0.47{\ensuremath{\mu}}_{B}$ for ${\mathrm{Mn}}_{2}\mathrm{Ga}$. The increase in the saturation magnetization as the Mn content is reduced indicates a ferrimagnetic order with partially compensating moments of the two different Mn atoms on the two crystallographically different sites of the ${\mathrm{DO}}_{22}$ structure. This type of magnetic order is supported by ab initio calculations of the electronic structure that predict a nearly half-metallic ferrimagnet with the highest spin polarization of 88% at the Fermi energy for ${\mathrm{Mn}}_{3}\mathrm{Ga}$. The Curie temperature of the compounds is restricted to approximately $770\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ because of a structural phase transition to the hexagonal ${\mathrm{DO}}_{19}$ phase. Thermal irreversibilities between zero-field-cooled and field-cooled measurements suggest that the ${\mathrm{Mn}}_{3\ensuremath{-}x}\mathrm{Ga}$ series belongs to the class of magnetically frustrated ferrimagnets. The most pronounced magnetic anomaly is found for ${\mathrm{Mn}}_{3}\mathrm{Ga}$.

Structural, electronic, and magnetic properties of tetragonal Mn3-xGa: Experiments and first-principles calculations

Magnetic and transitional behaviors are investigated in Mn1.9Co0.1Sb intermetallic compound. Mn2Sb is a simple ferrimagnet with Neel temperature around 550 K. The Co-introduction results in the appearance of antiferromagnetic state, and therefore, the first-order magnetic transition occurs between antiferromagnetic and ferrimagnetic state, which can be induced by temperature/magnetic field, in Mn1.9Co0.1Sb alloy. Accordingly, a magnetic entropy change as high as 5 J kg−1 K−1 and a large magnetoresistance of 46% under the field change of 10 and 50 kOe are achieved, respectively.

Giant magnetocaloric and magnetoresistance effects in ferrimagnetic Mn1.9Co0.1Sb alloy

Mn2Sb is a ferrimagnet, and substitution of Co or Cr for Mn above the critical concentration results in the appearance of a spontaneous first-order magnetic phase transition from ferrimagnetic (FRI) to antiferromagnetic (AF) with decreasing temperature below Tt . At T

Volume magnetostriction at the AF–FRI metamagnetic transition in the itinerant-electron system Mn2−xTxSb (T=Co, Cr)

Mn2−xCrxSb exhibits an antiferromagnetic-ferrimagnetic transition of which the temperature can be changed by controlling the Cr concentration. Increasing the Cr content from x = 0.05 to 0.13 raises the transition temperature from about 180 K up to around room temperature. To suppress the inevitable ferromagnetic MnSb impurity phase, we partially replace Sb by In. Mn2−xCrxSb1−yIny alloys have an antiferromagnetic-ferrimagnetic transition and a narrow transition hysteresis and exhibit the inverse magnetocaloric effect. We examine the magnetocaloric effect from the magnetization and direct adiabatic temperature-change measurements.

The structural, magnetic, and magnetocaloric properties of In-doped Mn2−xCrxSb

The binary manganese-antimony (Mn-Sb) phase diagram was reinvestigated in the whole composition range using powder-XRD, DTA and SEM-EDX. The phase boundaries and melting temperatures of the ferromagnetic phases MnSb and Mn2Sb were modified by taking into account the new experimental data. Most of the reaction temperatures could be verified within a range of ±10 °C. Nevertheless, a few temperatures had to be revised, such as the eutectic reaction L → β-Mn + Mn
 2
 Sb at 893 °C and the eutectoid reaction β-Mn → α-Mn + Mn
 2
 Sb at 718 °C. The previously reported peritectic melting behavior of MnSb could be confirmed. The variation of the lattice parameters of the NiAs-(B8
 1
 ) type MnSb phase with composition was determined. A revised version of the of the Mn-Sb phase diagram is presented.

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Experimental Investigation of the Binary Mn-Sb Phase Diagram

This paper reports on the results of investigations into the influence of high pressures (up to 5.3 GPa) at T=300 K on the magnetic structure of the Mn2Sb pnictide. The crystal and magnetic structures of the Mn2Sb compound are studied using a direct neutron diffraction method. It is demonstrated that the magnetic ferrimagnet-antiferromagnet phase transition, which is observed in a number of Mn2Sb-based substitutional solid solutions upon chemical compression of the Mn2Sb crystal lattice, does not occur in the Mn2Sb compound under high pressures in the aforementioned range due to an anisotropic pressure-stimulated strain in the Mn2Sb lattice. At pressures P≥2.8 GPa, the Mn2Sb compound is characterized by a spin reorientation with respect to the tetragonal axis and the basal plane of the crystal lattice.

Neutron diffraction investigation of the magnetic structure of the Mn2Sb pnictide at high pressures

The magnetic structure of a new Mn3Sb compound in the Mn-Sb system being characterized by the ferromagnetic ordering of Mn I and Mn II magnetoactive atoms with magnetic moments differing in magnitude is determined by the neutron diffraction technique. The proposed model of magnetic structure is in agreement with the magnetometry data, Mossbauer spectroscopy, and principles of symmetry analysis.

Magnetic ordering in Mn3Sb determined by neutron diffraction data

Manganese cation binding energy, dispersion curves, total phonon spectrum, and temperature dependence of the lattice and magnetic contributions to specific heat of Mn2Sb have been calculated.

V. M. Ryzhkovskii

Papers

Neutron diffraction investigation of the magnetic structure of the Mn2Sb pnictide at high pressures

Magnetic ordering in Mn3Sb determined by neutron diffraction data

Lattice dynamics and specific heat of the manganese antimonide Mn 2 Sb