Effect of confinement on the Eu emission band D0→F0 in Eu-doped nano-glass-ceramics

We report a non-linear blue shift of the zero-phonon emission line ⁵D₀→⁷F₀ of Eu³⁺-dopant in Eu³⁺-doped nano-glass-ceramics in magnetic field up to 50 T. The shift is significantly larger in nano-glass-ceramics compared to its precursor glass, suggesting that the nanoceraming of the precursor glass decreases the effective mass of the f-electrons bands of Eu³⁺ resulting in their enhanced magnetic confinement. Moreover, the non-linear character of the magnetic field dependence of this blue energy shift denotes a spatial confinement of f-electrons wave-functions of Eu³⁺ dopants in the PbF₂-based nanocrystals of the nano-glass-ceramics where up to 90% of the dopants partition. The spatial confinement seems to be due to an admixture to the f-states of Eu³⁺ of its higher lying states of opposite parity which fall in the quantum well comprising of Eu³⁺-doped PbF₂ crystalline nanoparticles embedded in the surrounding glass network.