Near-Room-Temperature Colossal Magnetodielectricity and Multiglass Properties in Partially DisorderedLa2NiMnO6

Abstract

We report magnetic, dielectric, and magnetodielectric responses of the pure monoclinic bulk phase of partially disordered La2NiMnO6, exhibiting a spectrum of unusual properties and establish that this compound is an intrinsically multiglass system with a large magnetodielectric coupling (8%-20%) over a wide range of temperatures (150-300 K). Specifically, our results establish a unique way to obtain colossal magnetodielectricity, independent of any striction effects, by engineering the asymmetric hopping contribution to the dielectric constant via the tuning of the relative-spin orientations between neighboring magnetic ions in a transition-metal oxide system. We discuss the role of antisite (Ni-Mn) disorder in emergence of these unusual properties.

Magnetic short- and long-range order inPbFe0.5Ta0.5O3

“…In particular, magnetic ion dilution at the disordered B-site leads to rich magnetic phase diagram and magnetic ground states ranging from simple antiferromagnet to incommensurate structures 5 . Furthermore, spinglass properties have also been reported in some of the complex disordered perovskites [6][7][8] . More recently, our studies of the disordered antiferromagnet PbFe 1/2 Nb 1/2 O 3 (PFN ) demonstrated that long range antiferromagnetic order can co-exist with a spinglass state on the microscopic scale 9 .…”

Phase stability and B-site ordering in La2NiMnO6 thin films

“…From the element maps, the order and disorder of the B-site cations coexist in the film, as demonstrated by red arrows and white arrows, respectively. It is noted that the partial ordering of B-site cations has been reported for the monoclinic phase of LNMO, 15,17 while the orthorhombic phase of LNMO is B-site disordered.…”

“…13 The coexistence of rhombohedral and monoclinic/orthorhombic phase was observed in LNMO at room temperature. 1,4,14 Moreover, rhombohedral LNMO (R 3) and monoclinic LNMO (P2 1 /n) are partially B-siteordered; [15][16][17] rhombohedral LNMO (R 3c) and orthorhombic LNMO (Pbnm) are completely B-site-disordered. 14,18 To fulfill the demands for integrated devices, epitaxial thin films of LNMO have been fabricated on different substrates by pulsed laser deposition (PLD).…”

Intrinsic dielectric properties of magnetodielectric La2CoMnO6

“…In particular, La 2 CoMnO 6 (LCMO) and La 2 NiMnO 6 (LNMO) has a distinguished position among other members of the series, mainly because of their relative higher Curie temperature (T c 230K and 280K, respectively), and strong electrical-magnetic coupled phenomena like magnetoelectric (ME) 4 , magnetodielectric (MD) [5][6][7][8] , magnetoresistive (MR) 9 and colossal magnetoresistive (MCR) 10 effects.…”