Spin reorientation transition in dysprosium-samarium orthoferrite single crystals

We report the control of spin reorientation (SR) transition in perovskite $\mathrm{D}{\mathrm{y}}_{1\ensuremath{-}x}\mathrm{S}{\mathrm{m}}_{x}\mathrm{Fe}{\mathrm{O}}_{3}$, a whole family of single crystals grown by an optical floating zone method from $x=0$ to 1 with an interval of 0.1. Powder x-ray diffractions and Rietveld refinements indicate that lattice parameters $a$ and $c$ increase linearly with Sm doping concentration, whereas $b$ keeps a constant. Temperature dependence of the magnetizations under zero-field-cooling (ZFC) and field-cooling (FC) processes are studied in detail. We have found a remarkable linear change of SR transition temperature in Sm-rich samples for $x>0.2$, which covers an extremely wide temperature range including room temperature. The $a$-axis magnetization curves under the FC during cooling (FCC) process bifurcate from and then jump back to that of the ZFC and FC warming process in single crystals when $x=0.5\ensuremath{-}0.9$, suggesting complicated $4f\ensuremath{-}3d$ electron interactions among $\mathrm{D}{\mathrm{y}}^{3+}\text{\ensuremath{-}}\mathrm{S}{\mathrm{m}}^{3+},\mathrm{D}{\mathrm{y}}^{3+}\text{\ensuremath{-}}\mathrm{F}{\mathrm{e}}^{3+}$, and $\mathrm{S}{\mathrm{m}}^{3+}\text{\ensuremath{-}}\mathrm{F}{\mathrm{e}}^{3+}$ sublattices of diverse magnetic configurations. The magnetic properties from the doping effect on SR transition temperature in these single crystals might be useful in the material physics and device design applications.