Abstract:The acoustic band gap structures of Ni and Cu nanowire triangular arrays (NWAs) were investigated by the plane wave expansion method. The structures were proposed on the basis of metallic NWAs realized from the state-of-the-art nanotechnology. The band gaps with GHz frequency can be achieved. We find that, in XΓ direction, Ni arrays are more easily to obtain the wider z mode band gaps. In ΓM direction, Cu arrays are more easily to motivate xy mode band gaps and larger band gaps at high frequency area. In some filling fraction, the band gap frequencies with z mode and xy mode can be obtained. Structurally, the two dimensional square lattice NWAs are more advantageous to produce hypersonic band gaps