ABSTRACT
The local compressibility of (MnO6)8− octahedral cluster for Mn4+ ion in the octahedral Al3+ site of Sr4Al14O25:Mn4+ crystal is investigated by analyzing the dominant pressure dependence of R-line position (i.e. 2E→4A2 transition). The obtained local compressibility is much greater than that in Al2O3: Mn4+ crystal, suggesting that the average Al3+–O2− distance of the replaced (AlO6)9− octahedron in Sr4Al14O25 is much greater than that in Al2O3. By comparing the average Al3+–O2− distances
in the three octahedral Al3+ sites, Al4, Al5 and Al6, in Sr4Al14O25 crystal, we propose that the dominant substitutional site of Mn4+ ion is Al4 site which has the largest average Al3+–O2− distance. The results are discussed.
Disclosure statement
No potential conflict of interest was reported by the authors.