Crystal and magnetic structure of (1−x)BiFeO3–xSrTiO3(1−x)BiFeO3–xSrTiO3 (x=0.2, 0.3, 0.4 and 0.8)

• We have established part of the phase diagram for doping SrTiO3 into BiFeO3.
• (1−x)BiFeO3–xSrTiO3(1−x)BiFeO3–xSrTiO3 is isostructural with BiFeO3 up to x<0.4x<0.4, and cubic for x>0.85x>0.85.
• We have examined the evolution of ordered magnetic moment with T and x.

The effect of doping SrTiO3 into BiFeO3 on the magnetic and crystal structure has been explored using powder neutron diffraction for (1−x)BiFeO3–xSrTiO3(1−x)BiFeO3–xSrTiO3 where x=0.2, 0.3, 0.4, 0.6 and 0.8. While the data are not sensitive to the cycloidal component of the magnetic ordering, the evolution of the collinear antiferromagnetic moment of the G-type antiferromagnetic component with T and x   has been explored, as have structural parameters. It is found that for x≤0.4x≤0.4 pure phase samples form in the R3c cell, and for x  =0.8 a non-magnetic Pm3¯m phase is obtained. The x=0.6 sample gives a mixed phase. Through the R3c phase the magnetic structure does not change appreciably apart from the reduction of magnetic moment magnitude with the increasing T and/or x.

A simple phase diagram for (1−x)BiFeO3–xSrTiO3(1−x)BiFeO3–xSrTiO3 , where hexagons indicate the rhombohedral R3c phase and boxes the cubic phase. Filled symbols indicate magnetic ordering. The black arrow indicates TN for BiFeO3.Figure optionsDownload as PowerPoint slide