**Characterization of Sol-Gel Derived Calcium Hydroxyapatite Coatings Fabricated on Patterned Rough Stainless Steel Surface**

**Vilma Jonauske 1,\*, Sandra Stanionyte 2, Shih-Wen Chen 3, Aleksej Zarkov 1, Remigijus Juskenas 2, Algirdas Selskis 2, Tadas Matijosius 2, Thomas C. K. Yang 3, Kunio Ishikawa 4, Rimantas Ramanauskas 2 and Aivaras Kareiva 1**


Received: 16 April 2019; Accepted: 21 May 2019; Published: 24 May 2019

**Abstract:** Sol-gel derived calcium hydroxyapatite (Ca10(PO4)6(OH)2; CHA) thin films were deposited on stainless steel substrates with transverse and longitudinal patterned roughness employing a spin-coating technique. Each layer in the preparation of CHA multilayers was separately annealed at 850 ◦C in air. Fabricated CHA coatings were placed in simulated body fluid (SBF) for 2, 3, and 4 weeks and investigated after withdrawal. For the evaluation of obtained and treated with SBF coatings, di ffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray di ffraction (XRD) analysis, Raman spectroscopy, XPS spectroscopy, scanning electron microscopy (SEM) analysis, and contact angle measurements were used. The tribological properties of the CHA coatings were also investigated in this study.

**Keywords:** calcium hydroxyapatite; sol-gel synthesis; thin films; spin coating; surface roughness; simulated body fluid
