Chromium doped barium titanyl oxalate nano-sandwich particles: A facile synthesis and structure enhanced electrorheological properties

Chromium doped barium titanyl oxalate (BCTO) particles with sandwich-like morphologies were synthesized via a facile chemical co-precipitation method in the presence of acrylamide. The morphologies, structures as well as dielectric and electrorheological (ER) properties of the as-synthesized BCTO particles were studied as functions of the concentration of acrylamide. The results show that with increasing the concentration of acrylamide used in the chemical co-precipitation process, the morphologies of the as-synthesized products change from an irregular shape via sandwich-like structure to congeries of blocks, at the same time, the crystallinity and the BET surface area (SBET) exhibit maximal values. All these phenomena are reasonably explained in terms of the interaction between acrylamide and BCTO. Among the as-synthesized products with various morphologies, the BCTO sandwich-like particles show the strongest interfacial polarization and ER effect, which originate from their peculiar morphology and SBET.