Enhance electron-correlation effect on the ruby multiplet energy dependence on pressure

Pressure-dependent multiplet-excitation energies of α-Al2O3:Cr3+ by the first-principles method

“…The multiplet states are distinguished by different markers: 2 E for a circle, 2 T 1 for a cross, 4 T 2 for a triangle, 2 T 2 for a diamond, and 4 T 1(a) for a square. The different colors are adopted to show the different methods: red for this work, blue for the theoretical values by the DVME method, 30) and green, purple for the experimental values from Stephens et al 26) Forman et al 24,25) respectively. , which can be expressed as follows.…”

“…30, they examied the pressure dependence of multiplet-excitation energies in α-Al 2 O 3 :Cr 3+ by DVME method with the configuration-dependent corrections and correlation corrections. 30) They performed the geometry optimization of a cluster by CASTEP to incorporate the effects of applied pressure. DVME can reasonably predict the multiplet-excitation energies with high accuracy.…”

“…Figure 3 shows (a) F 0 , (b) F 2 , (c) F 4 , and (d) 10Dq as a function of pressure. Red circles represent the values obtained by our method, blue triangles stand for ones by DVME, 30) and black squares show values estimated from experimental optical spectra. 51) In the comparison with experimental analysis at 0.0 GPa, our method gave better agreement than DVME for dominant component of the modified Slater-Condon parameter F 2 , and 10Dq as shown in Figs.…”

“…The red markers represent the results of our structure optimization, the blue ones stand for theoretical values by CASTEP, and the black ones show the experimental values. 43) 032001-3 © 2024 The Japan Society of Applied Physics 30) and experimental analysis, 51) respectively. Least square lines are drawn in order to clearly see the dependence.…”

“…20,21) There are experimental and theoretical studies to understand the multiplet energies and pressure dependence of α-Al 2 O 3 :Cr 3+ . [22][23][24][25][26][27][28][29][30] Even apart from α-Al 2 O 3 :Cr 3+ , for example, we have experimental investigations to develop a highly sensitive pressure indicators. 3,31) We found that the pressure dependence mainly comes from the changes in the local structure around the TM impurity.…”