*2.4. Characterization of the HA Layer Formed on Various Substrates*

The morphologic and crystallographic features of deposited films were examined by SEM and XRD. The contact angle of the water droplets (20 μL) on the titanium surfaces was measured by a contact angle analyzer after each surface treatment.

#### 2.4.1. SEM Observation

The morphology of the titanium surface after SPT and the immersion treatments was examined using a scanning electron microscope (SSX-550, Shimadzu Corporation, Kyoto, Japan) with an acceleration voltage of 10 kV, after the samples were coated with gold.
