Mikrohärteuntersuchungen an Einkristallen der Verbindungen Tl3BX4, (B = V,Nb, Ta; X=S,Se)

Vickers microhardness measurements were performed on single crystals of compounds Tl₃BX₄ (B = V, Nb, Ta; X = S, Se). The anisotropy of the hardness on the (111)-plane was beyond the standard deviation. Besides the load-dependent Vickers hardness HV, the corrected, load-independent hardness HV_c was determined. Tl₃VS₄ showed the highest value of hardness (HV = 66 kp/mm² at 15 p load), the othe compounds differ only slightly in hardness.