Curie temperature enhancement of electron doped Sr${}_2$FeMoO${}_6$ perovskites studied by photoemission spectroscopy

Abstract

We report here on the electronic structure of electron-doped half-metallic ferromagnetic perovskites such Sr${}_{2-x}$La${}_x$FeMoO${}_6$ ($x$=0-0.6) as obtained from high-resolved valence-band photoemission spectroscopy (PES). By comparing the PES spectra with band structure calculations, a distinctive peak at the Fermi level (E${}_F$) with predominantly (Fe+Mo) t${}_{2g}^{\downarrow }$ character has been evidenced for all samples, irrespectively of the $x$ values investigated. Moreover, we show that the electron doping due to the La substitution provides selectively delocalized carriers to the t${}_{2g}^{\downarrow }$ metallic spin channel. Consequently, a gradual rising of the density of states at the E${}_F$ has been observed as a function of the La doping. By changing the incoming photon energy we have shown that electron doping mainly rises the density of states of Mo parentage. These findings provide fundamental clues for understanding the origin of ferromagnetism in these oxides and shall be of relevance for tailoring oxides having still higher T${}_C$.

References in corpus (9)

• Electronic Structure of Sr_2FeMoO_6
• Cationic ordering control of magnetization in Sr2FeMoO6 double perovskite
• Strong ferromangnetism and weak antiferroamgnetism in double perovskites: Sr${}_2$Fe{/it M}O${}_6$ ({/it M}=Mo, W and Re)
• Electronic structure study of double perovskites $A_2$FeReO${}_6$ (A=Ba,Sr,Ca) and Sr${}_{2}M$MoO${}_6$ (M=Cr,Mn,Fe,Co) by LSDA and LSDA+U
• Electronic and Magnetic Structures of Sr2FeMoO6
• Evidence of strong antiferromagnetic coupling between localized and itinerant electrons in ferromagnetic Sr2FeMoO6
• Effect of band-filling and structural distortions on the Curie temperature of Fe-Mo double perovkites
• Phase diagram and influence of defects in the double perovskites
• Electronic properties and Fermi surface of Ag(111) films deposited onto H-passivated Si(111)-(1x1) surfaces

Cited by in corpus (4)

• Origin of Magnetism and trend in $T_c$ in Cr-based double perovskites: Interplay of two driving mechanisms
• Mean field theory for double-perovskites
• Electronic self-doping of Mo-states in A2FeMoO6 (A=Ca, Sr and Ba) half-metallic ferromagnets - a Nuclear Magnetic Resonance study
• Orbital ordering and magnetic structures in $\LMFO$ and $\LWFO$ double perovskites