First order magneto-structural phase transition and associated multi-functional properties in magnetic solids

Abstract

We show that the first order magneto-structural phase transitions observed in various classes of magnetic solids are often accompanied by useful multi-functional properties, namely giant magneto-resistance, magneto-caloric effect and magneto-striction. We highlight various characteristic features associated with a disorder influenced first order phase transition namely supercooling, superheating, phase-coexistence and metastability, in several magnetic materials and discuss how a proper understanding of the transition process can help in fine tuning of the accompanied functional properties. Magneto-elastic coupling is a key element in this first order phase transition, and methods need to be explored for maximizing the contributions from both the lattice and the magnetic degree of freedom while simultaneously minimizing the thermomagnetic hysteresis loss. An analogy is also drawn with the first order phase transition observed in dielectric materials and vortex matter of type-II superconductors.

Colossal negative thermal expansion induced by magnetic phase competition on frustrated lattices in Laves phase compound (Hf,Ta)Fe2

“…The subtle compromise among individual phases gives rise to rich magnetic phase diagrams. In the vicinity of phase boundaries, moderate magnetic fields can induce a giant response, which is the origin of plenty of magnetic properties such as colossal magnetoresistance [1][2][3][4] . Magnetic frustration leading to high degeneracies usually promotes such competition and more intriguing magnetic behaviors are expected [5][6][7] .…”

Anomalies in magnetoelastic properties of DyFe11.2Nb0.8 compound

“…6 Due to interaction of the anisotropic orbital electron cloud around the Dy 3þ magnetic ion with the crystal field of the lattice, the strong magnetostructural coupling 11 can be reflected by the appearance of anomalies in the thermal expansion coefficients as observed here for DyFe 11.2 Nb 0. 8 . Figure 2(a) shows the temperature dependence of ac magnetic susceptibility under different DC fields.…”

“…8 While the magnetic properties of RFe 12Àx T x compounds have been reported in detail, relatively little attention has been paid to their magnetoelastic properties, especially in the regions around the spin reorientation temperatures. Here, we present a detailed investigation of the magnetic behaviours and magnetoelastic effects around the spin reorientation transitions in DyFe 11.2 Nb 0.8 .…”

The metamagnetic behavior and giant inverse magnetocaloric effect in Ni–Co–Mn–(Ga, In, Sn) Heusler alloys

“…Note that in general the physics of the magnetostructural transition is quite rich and leads to interesting ferroic and multifunctional properties of the alloys as has recently been discussed by Roy [18]. In particular magnetic Heusler alloys with martensitic phase transition may show cluster-spin glass features due to enhanced magnetic frustration in martensite and chemical disorder as has actually been observed in Ni-Co-Mn-(In, Sn) [8,19,20].…”