Theory of Curie temperature enhancement in electron-doped EuO

Abstract

We present a comparative, theoretical study of the doping dependence of the critical temperature $T_C$ of the ferromagnetic insulator-metal transition in Gd-doped and O-deficient EuO, respectively. The strong $T_C$ enhancement in Eu${}_{1-x}$Gd${}_x$O is due to Kondo-like spin fluctuations on the Gd sites, which are absent in EuO${}_{1-x}$. Moreover, we find that the $T_C$ saturation in Eu${}_{1-x}$Gd${}_x$O for large $x$ is due to a reduced activation of dopant electrons into the conduction band, in agreement with experiments, rather than antiferromagnetic long-range contributions of the RKKY interaction. The results shed light on possibilities for further increasing $T_C$.

Published version; 3 references added

References in corpus (6)

• Soft x-ray magnetic circular dichroism study on Gd-doped EuO thin films
• Simultaneous ferromagnetic metal-semiconductor transition in electron-doped EuO
• Epitaxial EuO Thin Films on GaAs
• Diagrammatic self-consistent theory of Anderson localization for the tight-binding model
• Effect of Gd doping and O deficiency on the Curie temperature of EuO
• The elevated Curie temperature and half-metallicity in the ferromagnetic semiconductor La${}_x$Eu${}_{1-x}$O

Cited by in corpus (2)

• Interface enhanced magnetic anisotropy in Pt/EuO films
• Growth of EuO single crystals at reduced temperatures