Mechanical properties of solid-state-synthesized strontium- and magnesium-doped lanthanum gallate

This paper has examined the room-temperature mechanical properties of La0.8Sr0.2Ga1-xMgxO3-delta (x = 0.1-0.2) that was synthesized by using a solid-state technique. The modulus of rupture (MOR) was measured over the range of x = 0.1-0.2 and decreased as the B-site dopant content increased. At x = 0.15, for example, the MOR Was 139 +/- 17 MPa, whereas at x = 0.2, an MOR value of 113 +/- 8 MPa was observed. This decrease is postulated as being caused by the increased lattice stress due to the increased magnesium concentration on the B-site, The fracture toughness of the sample decreased as the magnesium content increased; at x = 0.15, a fracture toughness of 1.63 +/- 0.2 MPa . m(1/2) was observed, whereas at x = 0.2, a value of 1.28 MPa . m(1/2) was obtained.