Structure and magnetic properties of AgFeP2O7

Crystal structure and orbital-singlet state of Ag x VP 2 O 7

“…Above about 20 K, they are nearly fitted with the Curie-Weiss law as shown by the dotted curves. These curves provide the Curie constants C listed in Table 4 and the antiferromagnetic Weiss temperatures T W smaller than 1.5 K. The small exchange coupling constants in this system are consistent with the structural properties described in Section 2.2 and in contrast with the case for MFeP 2 O 7 with the large antiferromagnetic couplings [8].…”

“…2(a) and (b) shows the crystal structures of AgVP 2 O 7 projected along the b-and a þ c-axes, respectively. The structure of AgVP 2 O 7 is isomorphous to that of AgFeP 2 O 7 [8] and it is built up from infinite rows of isolated VO 6 octahedra bridged by the P 2 O 7 groups formed from the P1O 4 and P2O 4 tetrahedra. The framework of these VO 6 octahedra and P 2 O 7 groups forms the characteristic hexagonal tunnels along the a þ c-direction in which the Ag atoms are located with a full occupancy.…”

“…This structure has the large tunnels that result from stacking of rings formed by the edges of three octahedra and four tetrahedra. Magnetic properties of iron phosphate system such as AgFeP 2 O 7 with high-spin Fe 3 þ have been studied and the strong antiferromagnetic interaction is pointed out [8]. Here, in addition to the superexchange coupling through the bridging phosphate group, the mechanism between Fe centers via the Fe-O-Ag-O-Fe pathway by the involvement of the d orbitals of Ag ions has been postulated.…”

A mixed indium–iron lithium diphosphate, In0.51Fe0.49LiP2O7

“…For physical properties and potential applications of A I M III P 2 O 7 (A I = Li, Na, K, Rb, Cs and Ag; M III = Al, Ga, Cr, Fe, In, Y) diphosphates, see: Terebilenko et al (2010); Hizhnyi et al (2008); Whangbo et al (2004); Vitins et al (2000). For isotypic structures, see: Tran Qui et al (1987); Rousse et al (2002).…”

Silver indium diphosphate, AgInP2O7

“…For properties of M I FeP 2 O 7 (M I = Na, K, Rb, Cs and Ag) diphosphates, see: Terebilenko et al (2010); Hizhnyi et al (2008); Whangbo et al (2004); Vitins et al (2000). For isotypic structures, see: Belkouch et al (1995); Gabelica-Robert et al (1982); Moya-Pizarro et al (1984); Mercader et al (1990).…”