Synthesis and thermal expansion of MZr sub 4 P sub 6 O sub 2 sub 4 (M=Mg, Ca, Sr, Ba)

Thermal-expansion measurements made on sintered samples of these new NZP or CTP ceramics by dilatometry, high-temp. XRD, and the laser speckle technique show an anisotropy in axial thermal-expansion coeffs. CaZr sub 4 P sub 6 O sub 2 sub 4 and SrZr sub 4 P sub 6 O sub 2 sub 4 show reverse anisotropy as well as opposite bulk thermal expansion: CaZr sub 4 P sub 6 O sub 2 sub 4 , negative and SrZr sub 4 P sub 6 O sub 2 sub 4 , positive at 25- 500 degrees C. SEM data include microstructure.