Polymorphs with a face-centered cubic structure at room temperature were prepared by heat treatment in a humid or H-containing atmosphere. The lattice parameter was 0.728nm. Infra-red studies of the cubic phases revealed the existence of a H bonding, within the crystal structure, which was expected to be important in stabilizing the cubic structure at room temperature. It was found that the ionic conductivities (table 168) were much higher for the cubic phases than for other polymorphs.

B.Zhu, B.E.Mellander, J.Chen: Materials Research Bulletin, 1993, 28[2], 321-8

 

 

 

Table 168

Ionic Conductivities of Li3PO4M3PO4

 

Temperature (C)

Polymorph

 (S/cm)

E (eV)

400

-Li3PO4

7.3 x 10-7

1.43

400

-Li3PO4

6.5 x 10-7

1.40

600

-Li3PO4

7.5 x 10-5

1.40

400

c-Li3PO4

2.1 x 10-3

0.51

600

c-Li3PO4

1.2 x 10-2

0.51