Optical Thermometry Based on Vibration Sidebands in Y 2 MgTiO 6 :Mn 4+ Double Perovskite

Mn 4+ -doped Y 2 MgTiO 6 phosphors are synthesized by the traditional solid-state method. Powder X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectrometer are employed to characterize the samples. The Mn 4+ -doped Y 2 MgTiO 6 phosphors show the far-red emission at ∼715 nm, which is assigned to the 2 E g → 4 A 2 spin-forbidden transition of Mn 4+ . The temperature-dependent luminescent dynamics of Mn 4+ is described by a complete model associated with electron–lattice interaction and spin–orbit coupling. The noncontact optical thermometry of Y 2 MgTiO 6:Mn 4+ is discussed based on the fluorescence intensity ratio of thermally coupled anti-Stokes and Stokes sidebands of the efficient ∼715 nm far-red emission in the temperature range of 10–513 K. The maximum sensor sensitivity of Y 2 MgTiO 6:Mn 4+ is determined to be as high as 0.001 42 K –1 at 153 K, which demonstrates potential applications for the optical thermometry at low-temperature environments.