The hydrothermal modification in Ca

The hydrothermal modification in Ca(NO3)2 solution yielded BaTiO3 particles surrounded by small CaTiO3 crystallites of 20–100 nm in diameter which act as seeds in the mrecrystallization process of the matrix material [5], thus improving the sintering process and favoring the evolution of a homogeneous microstructure of the resulting ceramic.<br>Therefore, the sintering of these modified BaTiO3 powders which are used to produce ceramic devices, having a positive temperature coefficient of resistivity (PTCR), can be regarded as a densification process followed by the recrystallization and growth of the sub-micrometer starting material to form grains of at least 5
m in diameter [7]. The properties of the final ceramics are not determined by the original modified starting BaTiO3 particles, but by the recrystallized grains.

The hydrothermal modification in Ca(NO3)2 solution yielded BaTiO3 particles surrounded by small CaTiO3 crystallites of 20–100 nm in diameter which act as seeds in the mrecrystallization process of the matrix material [5], thus improving the sintering process and favoring the evolution of a homogeneous microstructure of the resulting ceramic.<br>Therefore, the sintering of these modified BaTiO3 powders which are used to produce ceramic devices, having a positive temperature coefficient of resistivity (PTCR), can be regarded as a densification process followed by the recrystallization and growth of the sub-micrometer starting material to form grains of at least 5
m in diameter [7]. The properties of the final ceramics are not determined by the original modified starting BaTiO3 particles, but by the recrystallized grains.

在Ca（NO3）2溶液中的水热改性产生了BaTiO3颗粒，其周围有直径为20–100 nm的小CaTiO3晶体，这些晶体在基体材料的M再结晶过程中起到种子的作用[5]，从而改进了烧结过程，并有利于形成陶瓷的均匀微观结构。<br>因此，这些用于生产具有正电阻率温度系数（PTCR）的改性BaTiO3粉末的烧结可被视为一个致密化过程，随后再结晶和生长亚微米起始材料，以形成直径至少为5
m的晶粒[7]。最终陶瓷的性能不是由初始改性的钛酸钡颗粒决定的，而是由再结晶晶粒决定的。