An A-Site Mixed-Ammonium Solid Solution Perovskite Series of [(NH2NH3)x(CH3NH3)1-x][Mn(HCOO)3] (x=1.00-0.67)

The A-site mixed-ammonium solid solutions of metal-organic perovskites [(NH2NH3)(x)(CH3NH3)(1-x)][Mn(HCOO)(3)] (x = 1.00-0.67) exhibit para- to ferroelectric diffuse phase transitions with lowered transition temperatures from x = 1.00 to 0.67. These properties are due to the decreased framework distortion and polarization in their low temperature ferroelectric phases caused by the increased CH3NH3+ concentration.