A facile hydrothermal route to self-assembled ZnGa2O4 particles and their microwave application

Self-assembled porous ZnGa 2 O 4 particles were synthesized through a facile hydrothermal route in this work. The phase evolution and microstructure of specimens were identified by XRD and SEM. Various morphologies (i.e. porous, nanorods or spherical particles) and size (nano or micro-sized) could be rationally designed through altering the reaction conditions. Hydrothermal ZnGa 2 O 4 particles exhibited an outstanding microwave dielectric performance, i.e. a dielectric constant of 9.93, a Q   ×   f value of 73 000   GHz, and a τ f value of –68.7   ppm/   °C. What is more, the ZnGa 2 O 4 ceramics displayed a stable quality factor in the high temperature region (1400–1500   °C) due to the unique frame-structured ZnGa 2 O 4 particles. Therefore, they can be regarded as potential candidate materials for millimeter-wave device.