Temperature-dependent R-curve behavior of the lead-free ferroelectric 0.615Ba(Zr0.2Ti0.8)O3–0.385(Ba0.7Ca0.3)TiO3 ceramic

•The maximum fracture toughness of BZT–38.5BCT decreases with increasing temperature.•We observed an exclusively transgranular fracture for BZT–38.5BCT.•We correlate the ferroelastic shielding behavior with the ferroelastic properties.

The temperature-dependent crack growth resistance behavior of the lead-free (1 − x)Ba(Zr0.2Ti0.8)O3–x(Ba0.7Ca0.3)TiO3 (x = 0.385) ceramic was characterized using compact-tension specimens from 25 °C to 60 °C. The observed plateau fracture toughness at 25 °C was found to be approximately 37% lower than commercial Pb(Zr,Ti)O3. At elevated temperature, the maximum fracture toughness displayed a decrease, which was found to be related to the temperature-dependent elastic and ferroelastic properties. Mechanical measurements are presented that demonstrate decreasing effective switching strain, coercive stress and Young’s modulus with increasing temperature.