Abstract
Single crystals of the new Bi(III) phosphates, Rb
6Bi
4(PO
4)
2(P
2O
7)
3, have been isolated and their structure has been determined by X-ray diffraction techniques. This compound crystallizes in the monoclinic space group
P2
1/
c with
a=9.077(1)
Å,
b=9.268(2)
Å,
c=36.418(6)
Å,
β=95.75(1)° and
Z=8. The crystal structure is made up of BiO
5 and BiO
6 polyhedra sharing the corners with PO
4 tetrahedra and P
2O
7 diphosphate groups. The structure can be described as infinite anionic layers with composition [Bi
4(PO
4)
2(P
2O
7)
3]
∞
6− parallel to the [301] plane, connected via P–O–Bi bridges to form a three-dimensional open framework. This framework delimits tunnels running along [100] and [010] directions, where the rubidium ions reside. This compound exhibits a rubidium ion conduction but with rather low conductivity value
σ=2.45×10
−7
Ω
−1
cm
−1
at 640
K.