Tilt grain-boundary junctions with a 45 [001] misorientation were found in thin films which had been grown, by means of pulsed organometallic beam epitaxy, onto (100)MgO. The junctions appeared at pre-determined locations, due to modification of the orientation relationship between the thin film and substrate by low-energy Ar-ion irradiation of parts of the substrate before film deposition. Rutherford back-scattering spectrometric and atomic force microscopic results indicated that ion implantation was necessary in order to cause the epitaxy modifications. It was noted that the boundaries were generally free from precipitates and were well-structured at the atomic scale. Regardless of the average grain boundary inclination, it was observed that asymmetrical (110)(100) facets predominated in the junction microstructures.

B.V.Vuchic, K.L.Merkle, P.M.Baldo, K.A.Dean, D.B.Buchholz, R.P.H.Chang, H.Zhang, L.D.Marks: Physica C, 1996, 270[1-2], 75-90