Controllable growth of Ga wires from Cr2GaC-Ga and its mechanism

The controllable growth behavior of Ga wires from Cr2GaC-Ga composite is presented and interpreted. The wire growth behavior was found to be modulated by forming pressure which tunes the connectivity between free Ga and Cr2GaC grains, the growth direction and the barrier force. Among the samples formed under 0 MPa to 900 MPa, the one (sample S4) formed under 500 MPa grew densest Ga wires, because the pressure of 500 MPa produced optimum connectivity between free Ga and Cr2GaC grains, aligned 53% of Cr2GaC basal planes near the surface of the sample parallel to its surface, and at the same time the barrier force was not too big to suppress wires to sprout. A Ga wire growth mechanism based on a catalysis model proposed in our prior work is employed and further developed herein to interpret the experimental observations of wires' size, morphologies and growth behavior.