Effect of temperature and supersaturation on the growth of Sr(No3)2 (1Â 1Â 1) face in aqueous solution

The normal growth rate R, hillock slope p and step velocity v=R/p of spiral growth hillocks on the (1 1 1) face of a Sr(NO3)2 crystal growing in aqueous solutions were measured as a function of supersaturation σ for various growth temperatures Tg by in situ Michelson interferometry. At given temperatures, p and v increased linearly with σ and, thus, R was proportional to σ2 in the supersaturation range σ=0.40-3.0%. Based on these data, the step free energy αs and the step kinetic coefficient βs were calculated. In the temperature range Tg=10.5-37.3°C, the step free energy was almost constant. By assuming that growth hillocks consist of single-, double- and triple-arm spiral steps, the values of step free energy were estimated to be αs=4.0, 8.0 and 12 mJ/m2, respectively. Meanwhile, the coefficient βs increased exponentially with temperature. An Arrhenius plot showed a linear dependence of ln βs on 1/Tg in the temperature range studied, from which the activation energy of step advance was estimated as E=53kJ/mol.