New Theoretical Insights into the Crystal-Field Splitting and Transition Mechanism for Nd³⁺-Doped Y₃Al₅O₁₂

Abstract

There has been considerable research interest paid to rare-earth transition-metal-doped Y3Al5O12, which has great potential for application as a laser crystal of new-type laser devices because of its unique optoelectronic and photophysical properties. Here, we present new research conducted on the structural evolution and crystal-field characteristics of a rare-earth Nd-doped Y3Al5O12 laser crystal by using the CALYPSO structure search method and our newly developed WEPMD method. A novel cage-like structure with a Nd3+ concentration of 4.16% is uncovered, which belongs to the standardized C 222 space group. Our results indicate that the impurity Nd3+ ions are likely to substitute the Y3+ at the central site of the host Y3Al5O12 crystal lattice. The laser emission 4F3/2 → 4I11/2 occurring at 1077 nm is in accord with that of the experimental data. By introducing the proper correlation crystal field, three transitions, 4G5/2 → 4I9/2, 4F7/2 → 4I9/2, and 4S3/2 → 4I9/2, are predicted to be good candidates for laser action. These findings can provide powerful guidelines for further experiments of rare-earth-metal-doped laser crystals.

Unveiling the Local Structure and Luminescence Mechanism of Er3+-Doped LiYF4: A Promising Near-Infrared Laser Crystal

“…It cannot accurately describe the crystal field splitting, which requires us to explore further. We present the first such in-depth investigation of the crystal field (CF) splitting in Er 3+ -doped YLF using our developed WEPMD method. − For the Er 3+ ion, we have used the Hamiltonian (see eqs –) in the full basis of all 364 states arising from the 4f 11 configuration. Many energy levels have been measured in experiments by Couto dos Santos et al, and these Stark levels are employed during the fitting procedure.…”

“…To obtain the accurate Stark levels of YLF:Er 3+ , our developed WEPMD method was introduced to calculate the energy levels, − and this method has been successfully applied to the systems of lanthanide ions doped into various crystals we studied previously. − For the Er 3+ -doped LiYF 4 system, Er 3+ ions replace Y 3+ ions in sites with the S 4 local symmetry, and the Hamiltonian is given in eqs – where Most of the parameters ( E AVE , F k , ζ nl , α, β, γ, T i , P j , and M n ) in the atomic Hamiltonian were described in our previous study. − The S 4 point symmetry of Er 3+ in YLF can indirectly infer the corresponding nonvanishing parameters of the crystal field (CF) Hamiltonian. In combination with free-ion (FI) parameters, it is worth mentioning that the total number of parameters is 22 for the energy level fitting of Er 3+ -doped LiYF 4 , and only six nonvanishing crystal field parameters (CFP) have to be considered in the S 4 symmetry.…”

“…Here, in this paper, a unique Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) − is proposed to predict a novel ground-state structure for YLF:Er 3+ , which was identified by us for the first time. In addition, we employ a method for regulating the f-shell energy levels of YLF:Er 3+ by our newly developed well-established parametrization matrix diagonalization (WEPMD) method, − and we present the first such in-depth investigation of the Stark levels in Er 3+ ions in the YLF crystal. Furthermore, according to the Judd–Ofelt (J–O) theory, , the electric dipole (ED) transitions were systematically investigated to acquire the most efficient luminescence of Er 3+ ions at 809 and 990 nm.…”

Aluminate-Based Nanostructured Luminescent Materials: Design of Processing and Functional Properties

“…Garnets are also well-known as a host family for optical applications; these compounds are based on the combination of a rare earth oxide and a metal oxide, the most representative materials of this group are Y 3 Al 5 O 12 (YAG) and Y 3 Ga 5 O 12 (YGG). YAG may be doped with Eu [ 17 ], Ce [ 18 ], or Nd [ 19 , 20 ] to enhance performance. It is important to highlight that Nd-YAG is one of the most important laser crystals for generating a 1.06-μm NIR emission.…”

Smart white lighting and multi‐mode optical modulations via photochromism in Dy‐doped KNN‐based transparent ceramics

“…Therefore, it is of great interest to develop bulk materials with the advantages of simple packaging, good thermal stability, and high efficiency of heat conduction for LEDs. Nonetheless, frequently studied bulk luminescent materials are concentrated in glass‐ceramics, such as Y 3 Al 5 O 12 (YAG) and the derivatives 9–11 . To expand the functionalities in LEDs, especially WLEDs, it is of significance to explore novel luminescent bulks.…”