Magneto-dielectric effect in relaxor superparaelectric Tb2CoMnO6 film

Abstract

We report magneto-dielectric properties of partially B-site ordered monoclinic Tb2CoMnO6 double perovskite thin film epitaxially grown by metalorganic aerosol deposition technique.Transmission electron microscopy and electron energy loss spectroscopy mapping shows the presence and distribution of both Co 2+ and Co 3+ ions in the film, evidencing a partial B-site disorder, which was further confirmed by the observation of reduced saturation magnetization at low temperatures. The ferromagnetic Curie temperature, TC=110 K, is slightly higher as compared to the bulk value (100 K) probably due to an in plane tensile strain. Remarkably, a short range ordering of spins at T*~190 K>>TC was established and assigned to the B-site disorder in the film.Two different dielectric relaxation peaks have been observed; they merge at the same temperature T* of short range spin correlations. Moreover, an unexpected high temperature dipolar relaxorglass-like transition at T~T* was observed, at which a coupling to short range magnetic correlations results in a 4% magneto-dielectric coupling.

Magnetism and Thermal Transport of Exchange-Spring-Coupled La2/3Sr1/3MnO3/La2MnCoO6 Superlattices with Perpendicular Magnetic Anisotropy

“…In addition, the insulating behavior of the cation-ordered LMCO due to superexchange and the doubled unit cell led to a significantly lower thermal conductivity compared to that in LSMO (Figure 7). Further, no influence of magnetic field on thermal transport in LMCO is observable, which fits the absence of the CMR effect in Co/Mn-ordered double perovskites [62]. Finally, one can see in Figure 7 a clear peak in the thermal conductivity of LMCO around T = 105 K, i.e., close to the temperature of the structural (cubic-tetragonal) phase transition of the STO substrate.…”

Emergence of metamagnetic transition, re-entrant cluster glass and spin phonon coupling in Tb2CoMnO6

“…Furthermore, Tb 2 CoMnO 6 (TCMO) is less explored DP system compared to La and Y based DP [24][25][26]. Recently, some interesting properties such as; large rotational magnetocaloric effect (MCE), relaxor glass transition in TCMO have been reported [36][37][38][39].…”

A high-TC heavy rare earth monoxide semiconductor TbO with a more than half-filled 4f orbital

“…21–23 Below 20 K, the magnetization steeply increased similar to that of HoO. 11 Such an increase significantly below T C was also observed in the double perovskite Tb 2 CoMnO 6 , 24 whose magnetization emerged from the Co/Mn 3d magnetic sublattice near T C but from the Tb 4f magnetic sublattice at a lower temperature.…”