The influence of growth rate on the microstructural and magnetic properties of float zone grown ErFeO3 crystals

Erbium orthoferrite (ErFeO3) single crystals have been successfully grown by the floating zone technique using a four-mirror image furnace. Particular attention was given to the influence of the growth rate on the microstructural and magnetic properties of the crystals. The as-grown crystals were characterized using the X-ray Lane technique, scanning electron microscopy, energy dispersive X-ray analysis and vibrating sample magnetometry. The results indicate that the best quality crystals were prepared when the growth rate was 6 mm/h or less, since the use of higher growth rates (12, 18 and 24 mm/h) was found to result in the formation of second phase inclusions within the crystals. The magnetic properties of these crystals, as represented by the hysteresis loops, showed that the crystals grown at higher rates have significantly lower coercivities; this was attributed to the effect of the second phase in nucleating reverse magnetic domains and so aiding the demagnetization process. Overall, the results clearly demonstrate the importance of the correlation between crystal growth and physical properties for this material. (c) 2006 Elsevier B.V. All rights reserved.