The GaNMn 3 -Epoxy composites with tunable coefficient of thermal expansion and good dielectric performance

Abstract GaNMn 3 /Epoxy composites were prepared by using negative thermal expansion GaNMn 3 powders as the metallic filler. By increasing the loading level of GaNMn 3 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 GaNMn 3 -0.7 μm and 26 vol.% - 43 vol.% for GaNMn 3 -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.