Search

Two fluorophosphates, BaMPO 4 F (M = Cu, Co), have been synthesized by a conventional hydrothermal method, and they crystallize in the orthorhombic system with the space group P2 1 2 1 2 1 , exhibiting a tunnel structure built by distorted MO 4 F square-pyramids and PO 4 tetrahedra. The magnetic behaviors of the two compounds are investigated by means of magnetic susceptibility, magnetization, and heat capacity measurements. The results indicate that BaCuPO 4 F exhibits a paramagnetic behavior down to 2 K, while BaCoPO 4 F undergoes long-range antiferromagnetic ordering at 11.3 K and short-range magnetic ordering at ∼22 K.

Two new compounds Sr 2 Cu 5 (PO 4 ) 4 X 2 ·8H 2 O (X = Cl and Br) are synthesized by a conventional hydrothermal method. Sr 2 Cu 5 (PO 4 ) 4 Cl 2 ·8H 2 O crystallizes in the tetragonal system with a space group of P42 1 2, while Sr 2 Cu 5 (PO 4 ) 4 Br 2 ·8H 2 O crystallizes in the space group P4/nmm, which are found to have a similar framework of layered structure, in which the crown-like {Cu 5 (PO 4 ) 4 X 2 } building units connect to each other forming a 2D corrugated sheet with vacancies, while the Sr 2+ cations are located along the vacancies. The spin lattice of two compounds built by Cu 2+ ions shows a new type of corrugated square. Magnetic measurements confirmed that both Sr 2 Cu 5 (PO 4 ) 4 X 2 ·8H 2 O (X = Cl and Br) exhibit antiferromagnetic ordering at low temperatures. A fit of theoretical model shows exchange interaction J = -25.62 K for the Cl-analogue and J/k B = -26.47 K for the Br-analogue.

The family of Archimedean lattices has eleven numbers, yet several of these lattices have not been reported for transition metal oxides. Here, the last number of Archimedean lattice was firstly realized in a layered phosphate.