Composite materials containing particulate BaTiO3 inclusion were fabricated with BaZrO3-ZnO as the matrix. Giant anelastic responses (abrupt increase in modulus and damping vs. temperature) were observed after 75C aging for 24h in these composites in the temperature region far below the Curie point of BaTiO3. Anomalies disappeared after 185C aging for 4h. Such responses were attributed to the constraining negative-stiffness effect of the inclusion. An oxygen vacancy mechanism was analysed which was considered to be responsible for the negative-stiffness effect. The present work was novel in terms of the idea of manipulation of negative stiffness in ferroelastic inclusions to achieve the desired composite properties.

Giant Anelastic Responses in (BaZrO3-ZnO)-BaTiO3 Composite Materials. L.Dong, D.Stone, R.Lakes: EPL, 2011, 93[6], 66003