铝酸钇熔体的预处理对晶体中光弥散的影响

Effects of Pretreatment of YAP Melt on Light Scattering Points in the Crystals

本文对引上法生长的铝酸钇(YAP)晶体中光弥散点的成因与克服途径进行了研究。发现原料中碳化物(Al_4C_3)的存在是诱发晶体中光弥散点的主要原因,以及使熔体在含有少量氧的氮气氛中进行适度的过热预处理是克服晶体中光弥散点的十分有效的途径。

In YAP single crystals grown by Czochralski technique,thereare two types of scattering centers.One is scattering particles of large size(>1μm) which has already been reported by us.While the other is verysmall size (<1μm) light scattering points.Many experimental approacheshave been carried out to investigate the formation of the light scattering pointsand the way to get rid of them in the crystals.It is found that the existenceof carbide (Al_4C_3) in the raw material is the main reason for the formation ofthe light scattering points in the crystals.Therefore,appropriate superheatpretreatment of the YAP melt at nitrogen atmosphere containing a little oxygenhas been proved to be a very effectual method in the elimination of the lightscattering points in the crystals.