Sensitization of Nd³⁺ Luminescence by Mn⁴⁺ in Mn⁴⁺, Nd³⁺ Codoped K_0.5La_0.5SrMgWO₆

A series of Mn4+, Nd3+ codoped K0.5La0.5SrMgWO6 phosphors have been prepared by high-temperature solid-state reaction method. Under 468 nm excitation, near infrared emission bands centered at around 910 and 1064 nm are observed, assigned to the F-4(3/2)-> I-4(9/2) and F-4(3/2)-> I-4(11/2) transitions of Nd3+, respectively. The similarity between the excitation spectra in the 300-550 nm monitored at Mn4+ 697 nm emission and those monitored at Nd3+ 1064 nm emission as well as the lifetime shortening of Mn4+ emission with Nd3+ concentration increasing prove that the occurrence of the energy transfer sensitization from Mn4+ to Nd3+. In terms of the analysis results based on Dexter's theory and Inokuti-Horayama model, it is believed that the dipole-dipole interaction plays a key role in the energy transfer process.