Features of the porous morphology of anodic alumina films at the initial stage of disordered growth

Influence of Induced Local Stress on The Morphology of Porous Anodic Alumina at The Initial Stage of Oxide Growth

“…As seen from Table I, in the electrolyte temperature range from 5 °С to 40 °С, K 1 and K 2 are constant and approximately equal to 1.17 and 1.51 for the first and second groups of minor pores, respectively. According to Chernyakova et al, 24 a value of 1.17 for minor pores with a larger diameter is close to the theoretical value equal to 2/√3. Increasing T e , the average distribution of the three main pore diameters does not change significantly, but the deviation from these values increases more than twice (from ±0.3 to ±0.7).…”

“…The stress arising in the oxide layer in the porous alumina cells during the anodic film growth may affect the development and termination of minor pore growth, as suggested by Chernyakova et al 24 In this regard, the general pattern of stress distribution in the oxide layer in porous alumina cells was investigated. For such experiments, we used the effect of decreasing the chemical etching rate of the oxide layer in the case of increasing compression stress in the oxide structure.…”

“…It is a characteristic of the disordered pore growth at the initial stage of aluminum anodizing, at which three large groups of pores develop. 24 The larger diameter (D) of 20.3 nm has the major pores in the anodic aluminum oxide film. The two smaller diameters (d 1 and d 2 ) of 17.2 and 13.5 nm belong to the group of minor pores.…”

“…To clearly show how the electrolyte temperature affects the ratio of the diameters of the major and minor pores, we introduced the coefficients K 1 and K 2 equal to the ratio of the diameter of major pores (D) to the diameter of minor pores of group 1 or group 2 (d 1 or d 2 ) 24 (Table I):…”