High pressure photoluminescence of Ce3+-doped(Y1.725Tb0.575Ce0.05Gd0.65)Al5O12

Abstract Photoluminescence of Y 2.3− x Tb x Ce 0.05 Gd 0.65 Al 5 O 12 ( x  = 0 and 0.575) has been measured at room temperature under high hydrostatic pressure. Broad-band emission peaked at 550 nm has been observed under 457 nm excitation, related to inter-configurational transition from the lowest state of excited electronic configuration 5d 1 to the ground state of Ce 3+ ions. Under excitation of 325 nm, mainly sharp-line luminescence has been observed related to 5 D 4  →  7 F 6 , 5 D 4  →  7 F 5 , 5 D 4  →  7 F 4 and 5 D 4  →  7 F 3 transitions in Tb 3+ ions. Pressure induced red shift of the Ce 3+ emission approximately equal to −20 cm −1 /kbar, and much smaller shifts (approximately −1 cm −1 /kbar) of the energies of sharp lines related to the Tb 3+ luminescence have been observed.