[en] Thermal expansion measurements to 1200⁰C have been made by the Bureau of Mines of a wide selection of complex oxides of both the perovskite and spinel structures. These are compared with the thermal expansion of molybdenum and the molybdenum alloy TZM to find suitable expansion matches for oxide coating development. A dilatometric technique was employed which makes use of a measuring microscope, accurate to 5 x 10^-5 in. In general, the spinels display a closer expansion match with the metal than the perovskites. Magnesium orthochromite showed the closest match between 25 and 1000⁰C. Its expansion in this range is 13 percent greater than that of molybdenum and TZM. Of the 50 oxide compositions examined, only 12 had expansion coefficients within 20 percent of that of molybdenum. All of these were orthochromites except the perovskite, 3BaHfO₃ . BaZrO₃