Crystal growth and structure of the new ferrimagnetic oxyphosphate PbFe3O(PO4)3

Hassan El Haffid (1) , Matias Velázquez (1) , Olivier Pérez (2) , Abdelaziz El Jazouli (3) , Alain Pautrat (2) , Rodolphe Decourt (1) , Philippe Veber (1) , Oudomsack Viraphong (1) , Claude Delmas (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
3 Faculté des Sciences Ben M'sik [Casablanca]

A new oxyphosphate, PbFe₃O(PO₄)₃, has been discovered and its structure has been characterized by single-crystal XRD between 293 and 973 K (monoclinic, space groupP2₁/m, a = 7.5826 Å, b = 6.3759 Å, c = 10.4245 Å, β = 99.956°, Z = 2, at r.t.). Direct-current (DC) magnetic susceptibility and specific heat measurements performed on single crystals revealed an unusual sequence of second-order ferromagnetic-like phase transitions at T_c1 = 31.8 K, T_c2 = 23.4 K and T_c3 ≈ 10 K. Alternating-current (AC) magnetic susceptibility measurements suggest glass-like dynamics between ca. 20 K and T_c3.

Mots clés: Ferromagnetism; Magnetic properties; Phosphates; Phase transitions; Critical point phenomena

Domaines: Matériaux

Hassan El Haffid, Matias Velázquez, Olivier Pérez, Abdelaziz El Jazouli, Alain Pautrat, et al.. Crystal growth and structure of the new ferrimagnetic oxyphosphate PbFe3O(PO4)3. European Journal of Inorganic Chemistry, 2011, 2011 (36), pp.5486-5495. ⟨10.1002/ejic.201100815⟩. ⟨hal-00654216⟩