Mn2+ doped Zn3(PO4)2 phosphors: Irreversible thermochromic materials useful as thermal sensors

Mn2+ doped Zn3(PO4)2 phosphate exhibits a rich thermal history with numerous events. Following the dehydration of Zn3(PO4)2⋅4H2O hopeite at temperatures up to T = 400 °C, various allotropic forms α/δ → γ → β can be stabilized with irreversible transitions for a 600 °C ⩽ T ⩽ 1000 °C temperature range. Furthermore, in these different networks, a transition metal can occupy distorted tetrahedral (α/δ forms) and pentahedral sites as well as...