Simultaneous accommodation of Dy3+ at the lattice site of β‐Ca3(PO4)2 and t‐ZrO2 mixtures: Structural stability, mechanical, optical, and magnetic features

Structurally stable β‐Ca3(PO4)2/t‐ZrO2 composite mixtures with the aid of Dy3+ stabilizer were accomplished at 1500°C. The precursors comprising Ca2+, P5+, Zr4+, and Dy3+ have been varied to obtain five different combinations. The results revealed the fact that complete phase transformation of calcium‐deficient apatite to β‐Ca3(PO4)2 occurred only at 1300°C, whereas the evidence of t‐ZrO2 crystallization is obvious at 900°C. The dual occupancy of Dy3+ at β‐Ca3(PO4)2 and t‐ZrO2 structures was evident; however, Dy3+ initially prefers to occupy β‐Ca3(PO4)2 lattice until its saturation limit and thereafter accommodates at the lattice site of ZrO2. The typical absorption and emission behavior of Dy3+ were noticed in all the systems and, moreover, the surrounding symmetry of Dy3+ domains has been determined from the luminescence study. All the systems ensured paramagnetic response that is generally contributed by the presence of Dy3+. A gradual increment in the phase content of t‐ZrO2 in the composite mixtures ensured a significant improvement in the hardness and Young's modulus of the investigated compositions. Dual occupancy of Dy3+ at the β‐Ca (PO4)2/ t‐ZrO2 lattice ensuring the resultant structural stability until 1500°C.