Evolution of Magnetotransport Properties and Spin-Glass Behavior of the La_0.7-xNd_xPb_0.3MnO₃ System

Abstract

The effect of neodymium substitution on the lanthanum site in La 0.7−x Nd x Pb 0.3 MnO 3 perovskite polycrystalline has been systematically studied. The substitution of neodymium for lanthanum causes structure change from rhombohedral to orthorhombic. Ferromagnetism is suppressed as neodymium content increases. The magnetic order changes from a ferromagnetic long-range order with x = 0.0 to a spin-glass nature with x = 0.7. Besides, the ferromagnetic-paramagnetic transition temperature values are lower for the neodymium phases than for the lanthanum ones. Therefore, the introduction of neodymium degrades symmetry of the structure, diminishes the spin-coupling exchange interaction, and results in changes of magnetic properties. This fact is in good agreement with increasing the B value in Bloch's T 3/2 law and decreasing the spin-wave stiffness parameter D in quadratic dispersion relation.

Observation of spin-glass-like behavior inSrRuO3epitaxial thin films

“…The excellent fit to T 3/2 law is clearly observed in both the films even without the small T 2 correction, which implies the suppression of Stoner excitations. The fact that FC magnetization does not saturate at low temperature implies short-range spin ordering in SRO like spin glasses La 0.7−x Nd x Pb 0.3 MnO 3 (x = 0.5 and 0.7), which also follow Bloch's T 3/2 law [31]. The exchange interaction (J) between two neighboring Ru 4+ ions was calculated using spin-wave parameter, A = (0.0587/S)(k B /2JS) 3/2 , where S is the total spin of Ru 4+ and k B is Boltzmann's constant, and found to be 16.1 k B K and 21.37 k B K for [110] and [010] oriented films, respectively.…”

Mn2+‐induced room‐temperature ferromagnetism and spin‐glass behavior in hydrothermally grown Mn‐doped ZnO nanorods

“…This is due to the glassy state; the moments are randomly frozen such that it will take a longer time for the field to turn those spins along the field direction . In addition, the FC magnetization is not saturating at low temperature, which indicates the short‐range spin ordering in the material . In order to understand the spin‐glass ordering, the magnetization irreversibility ( M irr ) vs. the temperature is plotted.…”

Effect of the simultaneous substitution of two transition metals on the structural, magnetic and electrical properties of La0.6Sr0.4Mn1−2xCrxFexO3

“…However, at low temperature, the competition between ferromagnetic and antiferromagnetic interactions prevents the existence of a long-range magnetic order, resulting in the spin-glass configuration. As a consequence, at the highest levels of substitution (0.20 and 0.25), the ZFC and FC curves display irreversibilities, which indicate the existence of cluster-or spin-glass behavior with short-range spin order [36]. In addition to the antiferromagnetic interactions Mn 4 + -O-Cr 3 + , Cr 3 + -O-Cr 3+ , Fe 3 + -O-Mn 4+ , Fe 3 + -O-Fe 3 + and Fe 3+ -O-Mn 3 + , the irreversibility between the ZFC and FC curves may be caused by a canting of the magnetic moments of the Fe and Cr ions, as observed in La 1À x Nd x Fe 0.5 Cr 0.5 O 3 [37].…”