The normal growth rate R., hillock slope p and step velocity v = R/p of spiral growth hillocks on the (111) face of a Sr(No-3)(2) crystal growing in aqueous solutions were measured as a function of supersaturation sigma for various growth temperatures T-g by in situ Michelson interferometry. At given temperatures, p and v increased linearly with sigma and, thus, R was proportional to sigma(2) in the supersaturation range sigma = 0.40-3.0%. Based on these data, the step free energy alpha(s) and the step kinetic coefficient beta(s) were calculated. In the temperature range T-g = 10.5-37.3 degrees 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 alpha(s) = 4.0, 8.0 and 12 mJ/m(2) respectively. Meanwhile, the coefficient beta(s) increased exponentially with temperature. An Arrhenius plot showed a linear dependence of ln beta(s) on l/T-g in the temperature range studied, from which the activation energy of step advance was estimated as E = 53 kJ/mol. (c) 2005 Elsevier B.V. All rights reserved.