Long range ferromagnetic ordering in pulsed laser deposited La0.7Ca0.3Mn1−xRuxO3 thin films

We demonstrate the existence of the metal to insulator transition (TMIT) up to 30% of Ru substitution at the Mn site, while the ferromagnetic transition (TC) is sustained even beyond 30% Ru substitution in the pulsed laser deposited La0.7Ca0.3Mn1−xRuxO3 thin films. The presence of Ru(IV) and (V) states complementing the t2g and eg orbital parentage of Mn(III) and Mn(IV) brings about prolonged double exchange mediated magnetic and electronic interactions, as confirmed by the X-ray absorption spectra and a negative magneto resistance ratio (MR) up to 11% at TMIT even for 30% Ru substitution.