Carrier doping to pseudo-low-dimensional compound La2RuO5

TL;DR

This study explores hole doping in La2RuO5 via Cd substitution and high-pressure oxygen annealing, revealing limited changes in properties due to carrier compensation by oxygen deficiency.

Contribution

It demonstrates successful Cd doping up to x=0.5 in La2RuO5 and investigates the effects of high-pressure oxygen annealing on its electrical and magnetic properties.

Findings

Doped samples remained largely unchanged in properties.

High-pressure O2 annealing slightly reduced resistivity.

Doped carriers are compensated by oxygen deficiency.

Abstract

Hole carrier doping has been tried to pseudo-low-dimensional material La2RuO5 by substituting La3+ with Cd2+. Single phased samples of La2-xCdxRuO5 with x up to 0.5 have been successfully obtained and also high pressure O2 annealing has been performed to the x=0.5 sample. Although the formal ionic state of Ru is expected to increase from 4+ (at x=0) to 4.5+ (at x=0.5), the magnetic and electrical properties show no significant changes in as-sintered samples. In contrast, high pressure O2 annealed x=0.5 samples show a little reduction of electrical resistivity and the decrease of thermoelectric power at 260 K. From these results, it can be speculated that the doped carriers are mostly compensated by oxygen deficiency in as-sintered samples.