Structural Evolutions and Crystal Field Characterizations of Tm-Doped YAlO₃: New Theoretical Insights

Abstract

The recent renaissance of the use of rare-earth-doped yttrium orthoaluminate as an ideal laser material has generated significant interest; however, the unique structural features underlying many of its outstanding optical properties still require elucidation. To solve this intriguing problem, we performed a systematic first-principles study; the results of the study reveal a new stable phase for Tm-doped YAlO (YAP), of monoclinic Pm symmetry, with an 80-atom per unit cell. An unbiased CALYPSO structure search indicates that the Tm impurity ion tends to substitute the position of Y in the YAP crystal lattice. Electronic band structure calculations reveal that the insulated behaviors of YAP are significantly eliminated after doping the impure Tm ions, as evidenced by the minor energy gap of about 0.4 eV, which is close to the band gap energy of a 2 μm emitter source. On the basis of our developed crystal-field theory method, the 4f electronic structures and energies of Tm ions in the YAP crystal are calculated. The theoretical results indicate that the electric-dipole-induced transition H → H is mainly responsible for producing the light wave at approximately 2.3 μm. The present results provide an essential understanding of the rare-earth-ion-doped lasing materials and serve as a practical tool for further exploration of such materials.

Possible Martensitic Transformation in In2(Mo,W)X (X = Cr, Mn, Fe, Co, and Ni) Heusler Alloys

“…First-principles calculations have been widely used to study the physical properties of various compounds including the Heusler alloys, perovskite oxide, yttrium orthoaluminate, rhodium silicides, and carbon dioxide [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. To probe the cubic structural ground state and martensitic transition of In 2 (Mo,W)X (X = Cr, Mn, Fe, Co, and Ni) alloys, we carry out first-principles density-functional calculations with CASTEP code where the plane-wave basis set is implemented [27,28].…”

The Microstructure and Electronic Properties of Yttrium Oxide Doped With Cerium: A Theoretical Insight

“…The CALYPSO is able to successfully predict the stable structures only with given chemical composition of the system (Lu et al, 2013(Lu et al, , 2017. The detailed method of CALYPSO has been reported in many papers (Ju et al, 2016(Ju et al, , 2017(Ju et al, , 2019a. In this work, the structure searches are performed for Y 2 O 3 doped with Ce system at 80 atoms in one unit cell.…”

Pressure Effects on Structural, Electronic, Elastic, and Optical Properties of Cubic and Tetragonal Phases of BaZrO3

“…The first-principle calculation has been successful in accurate understanding of the structural stability, the physical properties of various compounds including perovskite oxide, yttrium orthoaluminate, rhodium silicides, and carbon dioxide, under external conditions (pressure or impurity) [14][15][16][17]. Our first-principles calculations are performed using density functional theory (DFT) within the plane-wave basis available in CASTEP code [18].…”