Spin glass behaviour and extrinsic origin of magnetodielectric effect in non-multiferroic La₂NiMnO₆nanoparticles

Abstract

We report magnetization, dielectric and dc transport properties of La(2)NiMnO(6) nanoparticles. Both dc and ac magnetization measurements indicated a metastable magnetic behaviour with random ferromagnetic and antiferromagnetic interactions below 110 K; critical slow-down, memory and rejuvenation properties signify the spin glass nature. The dc resistivity shows a semiconducting nature but the temperature dependent magnetoresistance (MR) shows a peak at the spin glass transition. The colossal dielectric property and its frequency dependence were interpreted using the Maxwell-Wagner (MW) interfacial polarization model. Impedance analysis along with magnetodielectric (MD) and magnetoresistance (MR) indicates that the observed MD originates from the combined effect of MR and MW interfacial polarization.

Room temperature magnetodielectric studies on Mn-doped LaGaO3

“…Further, this peak shifts systematically towards lower frequency side (see inset (i)) which points towards the presence of field induced dipolar relaxation. 24 It should be noted that all the measurements reported here, were repeated; the data and the observed difference in the magnetodielectric measurements are found to be consistent and well above the estimated error bar.…”

“…20,21 However G. Catalan 22 and Jang et al 23 provided the way to establish whether the observed MD effect is that of the intrinsic character of the sample or due to magnetoresistive effects or due to heterogeneous character of the sample. 24 Keeping above in view, here, we present the room temperature MD studies on Mn doped LaGaO 3 . It should be noted that pure LaGaO 3 is a well known dielectric material with very low value of dielectric loss.…”

Magnetic frustration and dielectric relaxation in insulating Nd2NiMnO6 double perovskites

“…Generally, relaxors contain permanent electrical dipoles in nanoscale region and the loss tangent (tand) peak position coincides with 00 peak position. 36,37 While previous reports suggest a relaxor-like behaviour for Nd 2 NiMnO 6 , 27,38 a large temperature separation is observed between the peak positions of 00 and (tand), as shown in the inset of Fig. 7(b).…”

Investigation of the intrinsic magnetodielectric effect in La2CoMnO6: role of magnetic disorder

“…[11][12][13] In these systems, the ferromagnetic (FM) property is governed by Goodenough-Kanamori 180 superexchange interactions among the B-site cations. 11,[15][16][17][18] Recently, Chandrasekhar et al have reviewed the effect of dimensionality on the magnetic transition and MD behaviour. The ordering depends on the synthesis conditions, doping on La or B 0 /B 00 sites and particle size.…”