Electron-Hole Asymmetry in GdBaCo_{2}O_{5+x}: Evidence for Spin Blockade of Electron Transport in a Correlated Electron System

Abstract

In RBaCo_{2}O_{5+x} compounds (R is rare earth) variability of the oxygen content allows precise doping of CoO_2 planes with both types of charge carriers. We study transport properties of doped GdBaCo_{2}O_{5+x} single crystals and find a remarkable asymmetry in the behavior of holes and electrons doped into a parent insulator GdBaCo_{2}O_{5.5}. Doping dependences of resistivity, Hall response, and thermoelectric power reveal that the doped holes greatly improve the conductivity, while the electron-doped samples always remain poorly conducting. This doping asymmetry provides strong evidence for a spin blockade of the electron transport in RBaCo_{2}O_{5+x}.

4 pages, 5 figures, accepted for publication in PRL

References in corpus (5)

• Achieving fast oxygen diffusion in perovskites by cation ordering
• Transport and magnetic properties of GdBaCo_{2}O_{5+x} single crystals: A cobalt oxide with square-lattice CoO_2 planes over a wide range of electron and hole doping
• Selective Spin-State Switch and Metal-Insulator Transition in \boldmath $\mathrm{GdBaC}{\mathrm{o}}_2{\mathrm{O}}_{5.5}$
• Ising-like Spin Anisotropy and Competing Antiferromagnetic - Ferromagnetic Orders in GdBaCo_{2}O_{5.5} Single Crystals
• Non-equilibrium transport through a vertical quantum dot in the absence of spin-flip energy relaxation

Cited by in corpus (9)

• Origin of the large thermoelectric power in oxygen-variable RBaCo_{2}O_{5+x} (R=Gd, Nd)
• Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo2O5.5 with R=Y, Tb, Dy, and Ho
• Large magnetothermal conductivity in GdBaCo_{2}O_{5+x} single crystals
• First principles study of the spin state transitions in GdBaCo${}_2$O${}_{5.5}$
• Microscopic examinations of Co valences and spin states in electron-doped LaCoO${}_3$
• Prominent electron-hole asymmetry in thermoelectric transport of LaCoO${}_3$
• Proof-of-concept thermoelectric oxygen sensor exploiting oxygen mobility of GdBaCo2O5+δ
• Carrier filtering effect for enhanced thermopower in a body-centered tetragonal ruthenate
• Electron doping induced magnetic glassy state in phase separated YBaCo${}_2$O${}_{5.5-\delta }$