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The hydrothermal synthesis and magnetic, dielectric and ferroelectric property characterization of ABO3-perovskite GdFe1−xCrxO3 (0 ＜ x ＜ 1) are reported. The mineralizer KOH plays a critical role in the perovskite structure of the sample. The Fe/Cr ratio of the final crystal is controlled by the alkalinity in the initial reaction mixtures. The lattice parameters and magnetic ordering transition temperature have a close relationship with the Fe/Cr ratio. The temperature dependent magnetic properties of GdFe1−xCrxO3 (0 ＜ x ＜ 1) samples show a close relationship with substituent ratios of Cr3+. The occurrence of ferromagnetic behavior in all of the as-prepared samples comes from the coexistence of canted-antiferromagnetism due to the double exchange effect of Fe–O–Fe and Cr–O–Cr and ferromagnetism due to superexchange interaction of Fe–O–Cr. A large spontaneous polarization was observed in GdFe1−xCrxO3 at room temperature, exhibiting a clear ferroelectric hysteresis loop, which indicates the ferroelectric behavior in this system. This work not only provides an effective route to the controllable synthesis of B-site doped REFe1−xCrxO3 perovskite structure materials, but also presents a comprehensive study of the tunable effect of ionic doping on ferroelectric properties. [ABSTRACT FROM AUTHOR]

Perovskite structured rare-earth chromites (RECrO3) are an interesting family of functional materials due to their wide application in numerous areas. Various methods have been used to synthesize this family of materials; however, such methods usually need a high temperature crystallization process above 800 °C, and only produce polycrystalline ceramics. Herein, a series of RECrO3 single crystal samples with uniform particle sizes were prepared via a mild hydrothermal method with temperatures as low as 240–260 °C, and the synthesis conditions were studied in detail. Samples of LaCrO3, PrCrO3, and NdCrO3 were indexed to the Pnma space group, whereas SmCrO3 was indexed to Pbnm. The shapes of the crystals changed from cubic to plate as a result of the crystal lattice distortions induced by the reduction in the size of the A-site rare-earth cation. Raman spectra of the samples showed characteristic vibration modes of CrO6 clusters. Temperature dependent magnetization studies showed a transition from antiferromagnetism to paramagnetism in all the samples. Higher maximum and residual magnetization was achieved in all the hydrothermally prepared samples compared with those prepared by other methods. [ABSTRACT FROM AUTHOR]