A Novel Open-Framework Cerium Phosphate Fluoride: (NH4)[CeIVF2(PO4)]

The interlanthanide perovskites LaHoO3, LaErO3, LaTmO3, LaYbO3, LaLuO3, CeTmO3, CeYbO3, CeLuO3, PrYbO3, and PrLuO3 were prepared by the coprecipitation method. Their magnetic susceptibility measurements were carried out in the temperature range between 1.8 and 300 K, and it was found that LaYbO3, CeYbO3, and PrYbO3 had antiferromagnetic ordering with a weak ferromagnetism at 2.7 K. LaErO3 also showed antiferromagnetic ordering at 2.4 K. Specific heat measurements for LaErO3 and LaYbO3 showed the LAMBDA-type anomaly at 2.4 and 2.7 K, respectively, which is in good agreement with the susceptibility measurements.