engleski

Semiconducting properties of passsive films on AISI 304 and 316 stainless steels

Passive films on AISI 304 and 316 stainless steels in a near-neutral 0.5 M NaCl solution were studied using potentiodynamic, impedance and photoelectrochemical techniques. The results obtained indicate that passive films on both steels show the characteristics of an amorphous or disordered n-type semiconductor. The passive film on molybdenum-containing stainless steel has a lower donor concentration than that on 304 stainless steel. During the ageing process the donor concentration in passive films on both steels decreases. The shift of the Mott-Schottky line with pH change and consequently the pH dependence of the flat-band potential is assumed to be caused by an acid-base equilibrium established at the passive film/solution interface. Potential dependence of the optical gap value is observed and is interpreted on the basis of the passive film composition.

stainless steel ; passivity ; semiconducting properties

nije evidentirano