Upconversion emission and paramagnetism of colloid Ba₂ErF₇ and Ba₂ErF₇:Yb³⁺ nanocrystals synthesized with solvothermal method

Abstract

Ultrasmall near-monodisperse Ba₂ErF₇ nanocrystals with average crystal size 9.6 nm were synthesized with solvothermal method. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) assays reveal that the as-synthesized Ba₂ErF₇ nanocrystals are of the cubic structure with the cell parameter of 5.943 Å, instead of the reported orthorhombic and tetragonal structure. Two emission bands originated from ²H_11/2/⁴H_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 of Er³⁺ can be observed under a 980 nm laser excitation. The magnetic mass susceptibility of the as-synthesized Ba₂ErF₇ nanocrystals reaches 4.293×10⁻⁵ emu g⁻¹ Oe⁻¹.

Keywords

Ba₂ErF₇ / nanocrystal / upconversion / paramagnetism

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