The grain size of the porous layer is about 2nm and the thickness lamellar layer is a few tens of nanometer.

• 多孔羟基磷灰石层是由纳米晶粒构成的，平均晶粒尺寸大约2纳米。花瓣状羟基磷灰石层由约几十纳米大小的晶粒构成。