Surface influence on the behavior of stabilized zirconia nanoparticles under pressure

The surface state of partially stabilized zirconia with nanoparticles of sizes 10-30 nm after temperature and pressure treatments was investigated by Fourier transform infrared spectroscopy, X-ray diffraction and small-angle X-ray scattering. It is shown that the synthesized nanoparticles are surface fractals and the fractal dimensions non-monotonically change with nanoparticles size change. The martensite tetragonal-to-monoclinic transition of the partially stabilized zirconia nanoparticles under hydrostatic pressure (100-1000 MPa) was investigated. It was shown that the character of the martensite transition in nanoparticles' system depends on the pressure values. Three ranges of pressures were revealed. It was shown that the stability of martensite tetragonal-monoclinic transition decreases with the increase in size of the nanoparticles only for the pressures range of 300-500 MPa. Below 200 MPa, the character of the martensite transition is extreme and has a maximum for the particle size of 17 nm. In pressure range of 600-1000 MPa, the degree of martensite transition is dependent on the fractal dimension of the surface.