2000/12/25 by Y. Lyanda-Geller, Yuli Lyanda-Geller, Seung‐Hyun Chun +8 · 3 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Atomic and Subatomic Physics Research #Magnetic and transport properties of perovskites and related materials #cond-mat.dis-nn #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.184426
29 pages, 20 figures
arxiv created 2000/12/25 · openalex publication_date 2001/04/20 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The low-temperature Hall resistivity \ensuremathρxy of La2/3A1/3MnO3 single crystals (where A stands for Ca, Pb, and Ca, or Sr) can be separated into ordinary and anomalous contributions, giving rise to ordinary and anomalous Hall effects, respectively. However, no such decomposition is possible near the Curie temperature which, in these systems, is close to metal-to-insulator transition. Rather, for all of these compounds and to a good approximation, the \ensuremathρxy data at various temperatures and magnetic fields collapse (up to an overall scale), on to a single function of the reduced magnetization m\ensuremath≡M/Msat, the extremum of this function lying at m\ensuremath≈0.4. A mechanism for the anomalous Hall effect in the inelastic hopping regime, which reproduces these scaling curves, is identified. This mechanism, which is an extension of Holstein's model for the ordinary Hall effect in the hopping regime, arises from the combined effects of the double-exchange-induced quantal phase in triads of Mn ions and spin-orbit interactions. We identify processes that lead to the anomalous Hall effect for localized carriers and, along the way, analyze issues of quantum interference in the presence of phonon-assisted hopping. Our results suggest that, near the ferromagnet-to-paramagnet transition, it is appropriate to describe transport in manganites in terms of carrier hopping between states that are localized due to the combined effect of magnetic and nonmagnetic disorder. We attribute the qualitative variations in resistivity characteristics across manganite compounds to the differing strengths of their carrier self-trapping, and conclude that both disorder-induced localization and self-trapping effects are important for transport.