Mixed crystals of NaCl and KCl were grown from the water solution. The x-rays studies by Laue and powder patterns showed the existence of two phases viz NaCl and KCI in the crystals. The distribution of the phases was studied by optical and etching techniques. These observations of microstructures showed two distinct rypes of regions existing in stripes of varying widths. These stripes appear on {loo} faces lengthwise along

No abstract

Mixed NaCI-KCI crystals are grown from water solution. Thermal diffusion, decomposition and microstructures studies by employing the etching technique are reported. It is shown that microstructures consisting of alternate lameUae of NaCl and KCI arranged in directions in the two-phase mixed NaCI-KCi crystals observed at room temperature get converted to the one Consisting of random mixture of both the phases on finer scale on heating at 300°C for 30 hr. The dissociated matrix on heating at ~0°C for 15 hr regains almost all the characteristics of a single crystal transforming the material into single-phase mixed (Nag.)CI crystals. The temperature dependence of the thermal diffusion is discussed.

No abstract

Mixed solution-grown two-phase NaCl-KCl crystals are found to be structurally different from the melt-grown single-phase (NaK)Cl crystals. In the mixed crystal, quench hardening increases steadily with temperature which contrasts with the appearance of the plateau at 250-450 degrees C in pure NaCl and pure KCl crystals. These studies suggest that more than one mechanism is predominant in the mixed crystal. It is found that the interactions between the interphase diffused ions acting as impurities in the other phase and the dislocations, as well as the misfit strains introduced by these ions, contribute mainly to the hardening mechanism. Etching studies carried out also supported this finding.