Fig. 7From: Controlled Hydrothermal Synthesis and Photoluminescence of Nanocrystalline ZnGa2O4:Cr3+ MonospheresFE-SEM micrographs (a–d) showing morphologies of the 0.2ZGC products obtained after a 6, b 12, c 18, and d 24 h of reaction at 180 °C. The Cit3−/M molar ratio R is 1.0, and the system pH is 5 in each case. e is the size distribution of sample c obtained via dynamic laser scattering. d is the same sample of Fig. 4a but viewed under a lower magnificationBack to article page