A method to estimate compositional fluctuation in (Ti1-x, Zrx) B2 system using a value of the width of the fluctuation of lattice spacing was developed. This system forms a complete solid solution. All the compositions have hexagonal symmetry. The fluctuations of lattice spacings of (hk·0) planes and (00·l) planes have different values, because the dependencies of a-spacing and c-spacing on the composition are different. The compositional fluctuation was determined from the measured values of the fluctuation of the lattice spacings. Effect of the mechanical strain on the determination of the compositional fluctuation was examined, because the mechanical strain also affects the measured values of the fluctuation of lattice spacings. The examination showed that the mechanical strain can be neglected in this measurement. Relation between measured compositional fluctuation and composition showed that (Ti0.5Zr0.5) O3 had largest compositional fluctuation for samples prepared under the same conditions. (Ti1-x, Zrx) B2 by spark plasma sintering had smaller compositional fluctuation compared with those by hot press sintering.
