XRD analysis of high purity germanium single crystals grown by Czochralsk method

A high purity germanium (HPGe) crystal was grown in a hydrogen atmosphere by the Czochralsk method. XRD 2θ scanning was used to determine the orientation of the grown crystal. XRD 2θ scanning results show that an extremely strong (400) peak at 2θ of 66.15 o was observed in three samples cut from the grown crystal, indicating that the crystals had orientation. However, there is a very weak (200) peak at 2θ of 31.56 o for the sample cut from the middle part of the crystal. According to the reflection and extinction law of germanium crystals with face-centered cubic lattice, the reflection of 200 should be forbidden. The presence of (200) peak at 31.56 o could have resulted from XRD multiple-beam scattering. Additionally, the ω-scanning technique was used to obtain the rocking curves at the fixed 2 θ of 66.15 o , which have shown