Luminescent Properties Of Rare Earth Ions And Manganese Ions Doped Luminescent Materials In High Magnetic Field

Rare-earth compound luminescent materials are widely used in light-emitting devices,laser crystals,solar energy conversion media,laser amplifiers integrated waveguides and biological detection and other fields due to their strong absorption ability,high conversion efficiency,wide emission spectrum?covering ultraviolet to infrared light?and stable physical and chemical properties.In recent years,with the rapid development of multifunctional materials and devices,magneto-optical dual-function materials have attracted more and more attention.However,the development of these fields focuses on the fluorescence intensity and spectral intensity of rare earth ions,and the physical mechanism behind it is still unknown.In order to explore the applications of rare earths and other novel luminescent materials in the fields of magneto-optical dual-function materials and devices,we have studied the doping of different luminescent ions(Er³⁺,Ho³⁺,Sm³⁺,Nd³⁺,Mn⁴⁺)using pulsed magnetic field magneto-optical measurement devices.The luminescent behavior of luminescent materials under strong magnetic fields at low temperatures has yielded some interesting results.The main work is as follows:?.Magnetic field induced fluorescence enhancement and theoretical researchIn this paper,the novel phenomenon that rare-earth ion-doped Er³⁺:YVO₄ fluorescence intensity is enhanced by two orders of magnitude in magnetic field is studied experimentally and theoretically.The fluorescence enhancement mechanism based on resonance absorption is proposed.First,the influence factors of the strong magnetic field on the media environment of the rare earth ions and the mathematical expression of the Hamiltonian are given.The crystal field of Er³⁺:YVO₄ host is simplified to the D_2d model,and the Er³⁺absorption at low temperature is also studied.The wave functions of the stark energy level of the Er ion spectral branch are calculated.Furthermore,ultilzing the calculated energy level wave function,theoretical prediction of the fluorescence intensity of Er³⁺:YVO₄ in the magnetic field is given.This article hopes that this exact method can be applied to the precise detection of the wave function of rare earth ions.In addition,the factors affecting magneto-optical properties such as doping concentration of rare earth ions,excitation conditions,temperature and crystal orientation were researched in this paper,and the enhancement of visible and infrared emission regions at a low magnetic field of 2.5 T is achieved.?.Fluorescence kinetics and magneto-optical characteristics of Ho³⁺IonsBased on the particular fluorescence phenomenon of Er³⁺ions in YVO₄ host,the fluorescence kinetics of Ho³⁺ions in YVO₄ host and GdVO₄ host were studied.Firstly,the selective expression of the Ho³⁺ion emission wavelength was found in Ho³⁺,Yb³⁺:GdVO₄host.Studies have shown that this special emitting region has different excitation characteristics from the conventional emission regions 660 nm and 545 nm of the Ho³⁺ion,and this selective expression of the emission wavelength is expected to expand the spectrum utilization of the optical multifunctional material.Secondly,the fluorescence up-conversion effect of Ho³⁺in two kinds of host was studied in this paper,and the relaxation process of Ho³⁺ion upconversion was confirmed,which provided theoretical guidance for Ho-related up-conversion studies.The fluorescence behavior of Ho³⁺ions in YVO₄ host and GdVO₄ host in magnetic field indicates that Ho ions are a potential candidate for magneto-optical materials.?.Magneto-optical characteristics of Sm³⁺ion and Nd³⁺ionIn order to study the magneto-optical properties of rare earth ions extensively,the optical and magnetic properties of YVO₄ host and GdVO₄ host with single doping of Sm³⁺and Nd³⁺ions were investigated.Firstly,the fluorescence dynamics of Sm³⁺ions at room temperature was analyzed.The crystal field parameters of Sm³⁺ions were calculated by using the fluorescence spectra of the crystals at low temperature.The convenience of the fluorescence spectra in the theoretical calculation of the Sm³⁺ion crystal field was analyzed.The difference in magneto-optical spectral intensity of Sm³⁺ions in the two substrates indicates that the host has a significant effect on the modulation of the magneto-optical characteristics of rare earth Sm³⁺ions.In YVO₄,the intensity decreases with increasing magnetic field,but increases with magnetic field in GdVO₄.The first constant remains unchanged,and then decreases when the magnetic field reaches a certain threshold.The characterization of magneto-optical behavior in the infrared region of Nd³⁺ions shows that the fluorescence intensity of Nd³⁺ions is less affected by the magnetic field.?.New micro area magnetic field measurement deviceIn view of the important applications of strong magnetic fields in physics,material science and material forming.From the perspective of practical applications,this paper combines the good optical properties and magneto-optical characteristics of rare earth-rich Mn⁴⁺ions,and developed a strong magnetic field calibration device working at room temperature.Firstly,the spectral characteristics of Mn⁴⁺ion at room temperature and low temperature are studied.The results show that the spectrum of Mn⁴⁺ion in the range of 4.2K-300 K displaed a sharp half-width,which is lower than 0.1 nm at low temperature and lower than 0.5 nm at room temperature to satisfy the standard of magnetic field calibration.The magnetic spectrum of the Mn⁴⁺ion phosphor shows that the Mn⁴⁺ion has good linear splitting behavior and good repeatability.Based on its stable and excellent properties,this paper developed a strong magnetic field calibration method with excellent performance,simple operation method and low cost using Mn-ion phosphor as medium.