1 Epitaxial growth of Cu ( 100 ) and Pt ( 100 ) thin

Pulsed laser deposition (PLD) has been used to grow epitaxially oriented thin films of Cu and Pt on (100)-oriented substrates of both SrTiO3 and LaAlO3. The resulting films have been characterized for their crystalline orientations using x-ray diffraction (XRD) and for their surface morphologies using atomic force microscopy (AFM). The diffraction results illustrated that purely epitaxial Cu(100) films could be obtained at temperatures as low as 100 oC on SrTiO3 and 300 oC on LaAlO3. In contrast to these Cu films, Pt films having an epitaxial (100) orientation were attained on LaAlO3(100) only when deposited at 600 oC; lower deposition temperatures led to Pt(111) growth. Scanning probe microscopy images showed that films deposited at higher temperatures consisted of 3D islands and that flat, layered films were obtained only for the lowest deposition temperatures. Importantly, Cu films deposited at 100 oC on SrTiO3(100) were both purely (100)-oriented and morphologically flat. Pt and Cu films displaying both epitaxial growth and smooth surfaces could be obtained on LaAlO3(100) only using a three-step deposition process. The crystalline and morphological features of Cu films are compared to the current and previous studies of Pt deposition, and the results interpreted in terms of the thermodynamic and kinetic differences between Cu and Pt. 1 e-mail: [email protected], Fax: (412) 268-7596