Skip over navigation

 

Shape and size dependence of the phase transition temperature for ferroelectric/ferromagnetic nanoparticles

Liping Liu (Rutgers), Lixin Hu (Rutgers University)

Mechanics of Phase Transforming and Multifunctional Materials

Tue 9:00 - 10:30

CIT 219

It has been observed experimentally that the Curie temperature of phase transition of ferroelectric/ferromagnetic particles depends on the size and shape of the particles. Based on the phenomenological theory of Landau, we present a simple model that quantitatively explain the size and shape dependence of properties of the phase transition temperature. The main new ingredient of the model lies in the surface energy associated with the free surface that is anticipated to be significant as the size of particles decreases. Unlike the depolarization energy that always lowers the phase transition temperature, the surface energy may increases or lowers the phase transition temperature depending on the transformation strain, the residual surface stress (tension or compression) and its temperature dependence.