NQR and magnetic characteristics of the solid solution of NaClO3-KClO3

The nuclear quadrupole resonance (NQR) was measured of the solid solutions of NaClO3-KClO3 in the range of concentrations from 0 to 100% molar of KClO3 in (NaClO3+ KClO3). The thermal diagram of the measured samples showed that the solubility of the components in each other is limited. It is shown that in up to 88.6% molar of KClO3 it is possible to identify signals at a frequency which almost exactly corresponds to the NQR frequency of NaClO3. From this concentration upwards the signals belong to the NQR frequency of KClO3. At the same time the width of the line shows anomalies in samples containing up to 10% KClO3 or up to 10% NaClO3. The broadening of the NQR line to the value of 35 kHz in this region was interpreted as a result of the prevalence of the size effect when the solid solution consists of a mixed crystal of one of the components with such a number of cations of the other component, which is sufficient to produce a chaotic array around the resonating 35Cl nucleus and such alterations of the electrical field gradient that they will widen the line. The dependence of solid solutions molar magnetic susceptibility on the concentration of KClO3 in NaClO3+KClO3 is not linear. It has a peak at the concentration that pertains to the eutectic state when the chaotic array of the ions Na+, K+, (ClO3)- around any of them reaches perfection. At this concentration Van Vleck's polarization paramagnetism is minimal and being positive the total negative value of material susceptibility is maximal. (author)