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Temperature °C 2200 2000 1800 -0 1910°C 0 3 10 1925°C 1070 13 19 V3Si 1600 1400 1200 1000 10 20 V Si-V binary phase diagram. Weight Percent Silicon 20 30 50 …… ~29 2010°C 1895°C 30 1670°C 1640°C 57 ~59 1160°C L 1677°C V5Si3 V6Si5 VSi₂ 40 50 60 Atomic Percent Silicon 70 60 1400°C 70 80 80 90 beper 1414°C 90 ~97 (Si)- 100 100 Si
e) Thick Vanadium (V) metal plate is attached on 600μm thick single crystalline Silicon (Si) wafer (-semi-infinite diffusion couple) and annealed in inert atmosphere at the temperature of 1200°C for 16hours (=> sufficient amount of time has elapsed so that local equilibrium is achieved in all interfaces). Based on the V-Si phase diagram given above, identify the phases A,B,C and D shown in the micrographs below. In addition, draw (schematically) the composition profile for Vanadium (V) over the diffusion couple (=reaction zone). (NB. Mark clearly the compositions of the phases at all interfaces!). (4p) B D Si →→Si V B A C HV mag spot WO det 15.00 KV 1000 x 60 14.1 mm BSED 50 μm Quanta A x 3,000 D C JEOL 15.0kV COMPO ND 10.8mm