Mossbauer and XRD studies on the effect of doping iron in KCaY(PO4)(2)

The effect of doping iron at the yttrium site in hexagonal KCaY(PO4)(2) is studied for various concentrations of x (0 less than or equal to x less tha n or equal to 1), of iron using Mossbauer and X-ray diffraction methods. Fo r low iron concentrations, very little changes in structure are seen but at x approximate to 0.1, onset of new peaks in the XRD pattern is observed. T he Mossbauer study of the doped samples reveals that iron has a solubility of up to 2.5% in the parent phase with any excess iron precipitating out to form a new and unknown phase. From a detailed analysis of the X-ray diffra ction pattern (corresponding to x = 1) of the latter phase, it is found tha t this phase is rhombohedral with the possible space group R3.