Nanoclustering phase competition induces the resistivity hump in colossal magnetoresistive manganites

Abstract

Using a two-band double-exchange model with Jahn-Teller lattice distortions and super-exchange interactions, supplemented by quenched disorder, at electron density $n=0.65$, we explicitly demonstrate the coexistence of the $n$ = 1/2-type ($\pi ,\pi$) charge-ordered and the ferromagnetic nanoclusters above the ferromagnetic transition temperature $T_{\mathrm{c}}$ in colossal magnetoresistive (CMR) manganites. The resistivity increases due to the enhancement of the volume fraction of the charge-ordered and the ferromagnetic nanoclusters with decreasing the temperature down to $T_{\mathrm{c}}$. The ferromagnetic nanoclusters start to grow and merge, and the volume fraction of the charge-ordered nanoclusters decreases below $T_{\mathrm{c}}$, leading to the sharp drop in the resistivity. By applying a small external magnetic field $h$, we show that the resistivity above $T_{\mathrm{c}}$ increases, as compared with the case when $h=0$, a fact which further confirms the coexistence of the charge-ordered and the ferromagnetic nanoclusters. In addition, we show that the volume fraction of the charge-ordered nanoclusters decreases with increasing the bandwidth and consequently the resistivity hump diminishes for large bandwidth manganites, in good qualitative agreement with experiments. The obtained insights from our calculations provide a complete pathway to understand the phase competition in CMR manganites.

6 pages, 6 figures

References in corpus (6)

• Unveiling First Order CMR Transitions in the Two-Orbital Model for Manganites
• The Distinct Effects of Homogeneous Weak Disorder and Dilute Strong Scatterers on Phase Competetion in the Manganites
• Exploiting B Site Disorder for Phase Control in the Manganites
• Domain Formation and Orbital Ordering Transition in a Doped Jahn-Teller Insulator
• Scaled frequency-dependent transport in the mesoscopically phase-separated colossal magnetoresistive manganite La_{0.625-y}Pr_yCa_{0.375}MnO_3
• Quantum percolation and magnetic nano-dropletstates in electronically phase-separated manganite nanowires

Cited by in corpus (2)

• Antiferromagnetism beyond classical percolation threshold in the site-diluted half-filled one-band Hubbard model in three dimensions
• Designing multi-level resistance states for multi-bit storage using half doped manganites