Bond layer for silicon based substrates

A bond layer (14) for a silicon based substrate (12) comprises a refractory oxide forming metal having a thickness of between about 0.1 to 10 micron. The refractory oxide forming metal comprise chromium, tantalum, niobium, silicon, platinum, hafnium, yttrium, aluminum, zirconium, titanium, rare earth metals, alkaline earth metals and mixtures thereof.