The GaNMn3-Epoxy composites with tunable coefficient of thermal expansion and good dielectric performance

GaNMn3/Epoxy composites were prepared by using negative thermal expansion GaNMn3 powders as the metallic filler. By increasing the loading level of GaNMn3 powders, the hardness and heat conductivity were improved comparing with that of neat epoxy. When the loading level lies in 42 vol.% - 58 vol.% for GaNMn3-0.7 μm and 26 vol.% - 43 vol.% for GaNMn3-2.3 μm, the composites present low thermal expansion (the absolute value of linear thermal coefficient is less than 10 ppm/K), weak dielectric loss (less than 0.04), and the dielectric constants exceed 25, exhibiting great potential for applications in embedded-capacitor fields.