Author :
Bamzai, Krishen Kumar ; Kotru, P.N. ; Wanklyn, B.M.
Abstract :
Results of Vicker´s microhardness (Hv), fracture toughness (Kc), brittleness (Bi), and dislocation etching characteristics on (110) and (001) planes of flux grown yttrium orthoferrite crystals are reported. The values of Hv, Kc, Bi are estimated to be 1235.08 Kg/mm2, 0.1912 gm/μm3/2, and 8.1955 μm-1/2, respectively, for (110) plane, whereas for (001) plane the values of Hv, Kc, and Bi are 1027.12 kg/mm2, 0.5975 gm/μm3/2, and 1.875 μm-1/2, respectively. The variation o Hv with applied load is explained to follow from the Hays and Kendalls law. Etching kinetics of YFeO3 surfaces in H3PO4 at different temperatures leads to activation energy values for etch pits; the activation energies for dissolution parallel to (110) and (001) planes (i.e., lateral dissolution EL) are 0.41 eV and 0.34 eV, respectively. The activation energies for dissolution perpendicular to (110) and (001) planes (i.e., vertical dissolution ED) are 0.20 eV and 0.21 eV, respectively
Keywords :
brittleness; crystal growth from solution; dislocation etching; ferrites; fracture toughness; hardness; yttrium compounds; (001) planes; (110) plane; Vicker´s microhardness; activation energy values; brittleness; dislocation etching; etch pits; flux grown YFeO3; fracture toughness; lateral dissolution; orthoferrite; Bismuth; Crystalline materials; Crystals; Electrical resistance measurement; Equations; Etching; Plastics; Pressure measurement; Stress measurement;
