Ls. Fomenko et al., MICROHARDNESS OF THE COMPOUNDS LA2CUO4 AND LA1.85SR0.15CUO4 AT TEMPERATURES FROM 81 TO 292 K, Physics of the solid state, 40(3), 1998, pp. 453-457
The microhardness of La2CuO4 and La1.85Sr0.15CuO4 crystals is measured
in the temperature range 81-292 K, and the influence of various facto
rs on it is investigated. The thermal activation parameters of the pla
stic deformation process in the vicinity of the indenter impression ar
e estimated. The change of the phase state of the compound La1.85Sr0.1
5CuO4 at the temperature T-0=180 K and the appearance of domain (twin)
boundaries formed in the ferroelastic tetra-ortho transition are not
seen in the temperature dependence of the microhardness, The results o
f the study are compared with previously published results for YBa2CuO
7-x crystals. (C) 1998 American Institute of Physics. [S1063-7834(98)0
1903-0].