The Bragg-Brentano arrangement of X-ray diffractometer is not suitable for film specimens because
Bragg-BrentanoX射线衍射仪不适用于薄膜样品，原因是？
A、the penetration of X-ray is too deep into the substrate
X射线的穿透深达基底
B、it detects the surface of specimen mainly
因为只能检测样品表面
C、film specimen does not need to follow the Bragg's law
薄膜样品不需要遵循布拉格定律
D、the beam is not monochromatic
该光束不是单色光