Published online by Cambridge University Press: 31 January 2011
Miniaturized monolithic langasite structures are micromachined using local doping of lan-gasite and wet chemical etching. The diffusion coefficients of niobium, strontium and praseodymium in langasite are determined in order to control the preparation process and to obtain information about the stability of locally doped structures at elevated temperatures. A wet etching process based on phosphoric acid for langasite is developed and used to manufacture microstructured elements like planar and biconvex membranes as well as field emitter diodes. These elements are characterized with respect to their application relevant properties such as resonator quality factor and field emission current at temperatures of 600 °C and above.