Stability characteristics of the low-temperature ferrimagnetism in the Mn2−xZnxSb system

Abstract

The magnetic properties of the system Mn2−xZnxSb are investigated experimentally in static and pulsed magnetic fields. It is found that the spontaneous first-order transitions from the ferro=imagnetic phase Fi to the weakly ferrimagnetic phase If which are observed on decreasing temperature in samples with x=0.1 and 0.2 are accompanied by an almost twofold decrease of the magnetization and magnetostriction with no change of the easy-plane character of the anisotropy. Studies of the effect of a pulsed magnetic field in the temperature region of stability of the weakly ferrimagnetic phase reveal reversible magnetic-field-induced first-order phase transitions If↔Fi. Quenching of the samples from 570K into liquid nitrogen enhances the stability of the weakly ferrimagnetic phase with respect to the influences of temperature and external magnetic field. This is manifested in an increase of the temperature of the spontaneous transition by 45 degrees and an increase in the critical field for its induction from 80 to 200kOe. As the quenched sample is heated to room temperature, the initial characteristics of the weakly ferrimagnetic phase are gradually restored. The results are analyzed in a model of itinerant magnetism with the use of first-principles calculations of the electron density of states and total energy of the system. It is shown that the weakly ferrimagnetic phase with the doubled crystal-chemical cell can be described by the Hubbard model. The properties of the quenched samples can be explained by assuming the presence of two stable states of the system, separated by an energy barrier and associated with the possibility of a redistribution of the zinc ions over two crystallographically inequivalent lattice positions.

Giant topological Hall effect in centrosymmetric tetragonal Mn2−xZnxSb

“…Therefore, the discovery of tetragonal layered magnetic materials with tunable spin textures is highly desired for better understanding of low dimensional magnetism. One promising class of materials is Mn 2−x T x Sb, where T is a transition metal such as Zn [24][25][26], Cr [27,28], Co [29], or Fe [30].…”

“…It displays a ferrimagnetic (FI) order with spins collinear along the c-axis below 550 K, and undergoes another magnetic transition with spins re-oriented within the ab plane below 240 K [31]. The substitution of Mn by other transition metals T tunes magnetic phases, which consequently modifies other properties such as cell volume [24], magnetostriction [32], electronic transport [24], and the magnetocaloric effect [33]. Such coupling of magnetism and physical properties, together with the layered structure and high electrical conductivity of these materials, makes Mn 2−x T x Sb a good material platform to study and tune the competing exchange interactions, as well as to develop new magnetic devices.…”

“…Among transition metals, the non-magnetic Zn substitution to create Mn 2−x Zn x Sb is particularly interesting. It has been reported that light Zn-substitution leads to a weak ferrimagnetic state at low temperatures [24]. Further increasing Zn content to x = 1 can fully suppress the anti-parallel magnetic sublattice, leading to ferromagnetic (FM) order with the Curie temperature of 320 K in MnZnSb [34,37].…”

Quasi-First Order Magnetic Transition in Mn_1.9Fe_0.1Sb_0.9Sn_0.1

“…Furthermore, a cusp of the M-T curve for μ 0 H = 0.1 T was observed in the vicinity of 225 K. According to the previous papers, this cusp is originated from the SR between the FRI(I) and FRI(II) phase. 5,11,14,21,22,25) Therefore, the FOMT was expected to the AFM-FRI(I) transition. The SR temperatures for the FC and FCW processes were determined to be T SR1 = 218 K and T SR2 = 227 K, respectively.…”

“…1. The SR phenomenon between the FRI(I) and FRI(II) states has been reported for Mn 2−x Co x Sb 5,25) , Mn 2−x Zn x Sb 11) , Mn 2−x Cu x Sb 21,22) and Mn 2 Sb 0.9 Sn 0.1…”