Modification of mechanical properties in PMNT 90:10 by substitution with La

Modern actuator systems require highly specialised, tailored electroceramic compositions, in order to realise their full potential. These modifications include many mechanical modifications, such as density adjustment, transparency, and grain size refinement. The work reported here describes a very simple method by which the Youngʹs modulus in the system Pb(Mg1/3Nb2/3)O3 can be accurately controlled, by substitution with low La concentrations onto the Pb site; substitution of 1 at% La raises the Youngʹs modulus from 98.6 to 116 MPa in the composition Pb(Mg1/3Nb2/3)0.9Ti0.1O3. This may be used to raise significantly the resonant frequency of an actuating system. La doping was also shown to increase the porosity, from 0.4 to 2.8%.