The Biaxial Strain Dependence of Magnetic Order in Spin Frustrated Mn₃NiN Thin Films

Abstract

Multicomponent magnetic phase diagrams are a key property of functional materials for a variety of uses, such as manipulation of magnetization for energy efficient memory, data storage, and cooling applications. Strong spin-lattice coupling extends this functionality further by allowing electricfield-control of magnetization via strain coupling with a piezoelectric. Here this work explores the magnetic phase diagram of piezomagnetic Mn 3 NiN thin films, with a frustrated noncollinear antiferromagnetic (AFM) structure, as a function of the growth induced biaxial strain. Under compressive strain, the films support a canted AFM state with large coercivity of the transverse anomalous Hall resistivity, ρ xy , at low temperature, that transforms at a welldefined Néel transition temperature (T N ) into a soft ferrimagnetic-like (FIM) state at high temperatures. In stark contrast, under tensile strain, the low temperature canted AFM phase transitions to a state where ρ xy is an order of magnitude smaller and therefore consistent with a low magnetization phase. Neutron scattering confirms that the high temperature FIM-like phase of compressively strained films is magnetically ordered and the transition at T N is first-order. The results open the field toward future exploration of electricfield-driven piezospintronic and thin film caloric cooling applications in both Mn 3 NiN itself and the broader Mn 3 AN family.

Effect of N, C and B interstitials on the structural and magnetic properties of alloys with Cu$_3$Au-structure

“…Further, we note that in the related compound Mn 3 GaN calculations by Zemen et al [78] have shown that a combination of strain and temperature leads to a stabilization of a ferrimagnetic ground state. A similar behaviour was recently also experimentally observed for a Mn 3 NiN film on a SrTiO 3 substrate [79]. In passing we note also that epitaxial strain in Mn 3 XN as well as in Mn 3 X (X=Rh, Ir, Pt) is accompanied by a significant net magnetization in the NC ground state, albeit smaller than the one predicted for Mn 3 SnN [80].…”

Electric‐Field‐Controlled Antiferromagnetic Spintronic Devices

“…Meanwhile, Boldrin et al systematically researched the interface‐induced strain effects on antiferromagnetic Mn 3 NiN thin films by growing it on different substrates 78,79. It was found that under biaxial or uniaxial strain, the symmetry of the antiperovskite structure ( Figure a) could be destroyed, which leads to changes in the Néel temperature (Figure 7b) and magnetization (Figure 7c).…”

“…Although the anomalous Hall effect in noncollinear antiferromagnets is of interest due to the exotic Berry curvature and in principle, the anomalous Hall resistance could be harnessed for information encoding in memory devices, the susceptibility of canted moments to magnetic fields in noncollinear antiferromagnets leads to the fact that the anomalous Hall resistance can be easily disturbed by external magnetic fields. Moreover, the electric‐field‐controlled anomalous Hall effect in noncollinear antiferromagnets has not been maturely realized at room temperature 20,78,79,81. Instead, the piezoelectric‐strain controlled longitudinal resistance40 using the anisotropic magnetoresistance effect can well overcome these two bottleneck issues.…”

Caloric effects around phase transitions in magnetic materials described by ab initio theory: The electronic glue and fluctuating local moments

“…Changing their crystal symmetry and relative interatomic distances via stress application can have a substantial impact on the geometrically frustrated magnetic interactions, which in turn strongly change the stability of frustrated and non-frustrated magnetic phases. This is the situation observed in the Mn-based antiperovskite nitride systems Mn 3 GaN and Mn 3 NiN 10, 51,52 . The unstrained form of these two materials show a firstorder PM-to-triangular AFM phase transition at T N 53,54 , shown in Fig.…”