Ion mixing in oxide-sapphire systems

Abstract

Ion beam mixing of thin oxide f'dms on sapphire substrates has been studied in order to examine any role of equilibrium thermodynamic parameters on the mixing process.Mixing experiments were performed with polycrystalline oxide films deposited on single crystalline o_-A1203substrates. According to the equilibrium phase diagrams, Cr203 is completely soluble in o_-A1203,while ZrO2 is insoluble. The couples we_'eirradiated with Cr ions (160 and 340 keV) or Kr ions to fluences of 4 x 1016ions/cm 2 at temperatures between 20 and 900°C. Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy, and transmission electron microscopy were used to analyze samples before and after irradiation to determine the extent and nature of interface modifications. No longrange mixing was detected under any condition studied; the width of the "mixed" region in each case was consistent with recoil mixing. The absence of long-range mixing is rationalized in terms of the different ranges of oxygen ions and cations.

Ion beam mixing at the Fe2O3/Al2O3 interface

“…24 The phase remains paramagnetic up to xϭ0.5 ͓Fig. 3͑d͔͒ at variance with Dehe et al 6 who have found sign of magnetic relaxation. The relative intensities of the two new components increase with x at the expense of Examination Figs.…”

“…[6][7][8] Very recently Joslin et al have studied ion beam mixing of 50 and 80 nm thin films of Cr 2 O 3 and ZrO 2 oxides deposited on sapphire substrates. 6 The choice of these two oxides was based on the considerations of equilibrium phase diagrams, according to which Cr 2 O 3 is completely soluble in ␣-Al 2 O 3 while ZrO 2 is insoluble. The mixing experiments were performed with 475 keV Kr ions at two fluences ͑4ϫ10 16 and 8ϫ10 16 ions/cm 2 ͒ and at room temperature or at 860°C.…”

Systematic study of the ion beam mixing of oxide markers into alumina

“…[12] [13] showed no detectable mixing in either system at 25 OC, but a small a amount of ballistic mixing i11 both systems at 860°C. The first indications ofthermslly assisted ion mixing were reported for Fe2O3 markers in AI203 [6] [7].…”