High-temperature VUV spectroscopy of KYF4 crystals doped with Nd3+, Er3+ and Tm3+ ions. (July 2016)

• Record Type: Journal Article
• Authors: Makhov, V.N.; Khaidukov, N.M.; Kirm, M.; Vielhauer, S.
• Is Part Of: Radiation measurements. Volume 90(2016:Jul.)
• Page Start: 298
• Page End: 302
• Publication Date: 2016-07
• Subjects: 5d-4f luminescence -- Thermal quenching -- Nd3+ -- Er3+ -- Tm3+ -- KYF4; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2015.12.016
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: Thermal quenching of 5 d -4 f luminescence from Nd 3+, Er 3+ and Tm 3+ ions doped into KYF4 crystals has been investigated in the temperature range up to ∼750 K where this luminescence is completely quenched. The obtained temperatures of thermal quenching ( T q ) are ∼270, 495, 450 K for Nd 3+, Er 3+, Tm 3+, respectively. At high temperatures, thermal quenching of 5 d -4 f luminescence from Nd 3+ and Er 3+ is accompanied by the appearance of 4 f -4 f luminescence from the lower-energy 4 f levels. It has been shown that the dominating mechanism of thermal quenching for Nd 3+ and Er 3+ ions is thermally stimulated non-radiative transitions (intersystem crossing) from the 5 d states to lower-energy 4 f levels, namely 2 G (2)9/2 and 2 F (2)7/2, respectively, whereas for the Tm 3+ ion, thermally stimulated ionization of 5 d electrons to the conduction band states is responsible for thermal quenching of 5 d -4 f luminescence. The energy gap between the lowest Tm 3+ 5 d level and the bottom of the KYF4 conduction band has been estimated to be 0.66 eV. Highlights: Quenching temperatures of 5 d -4 f luminescence from Nd 3+, Er 3+, Tm 3+ in KYF4 obtained. Thermal quenching for Nd 3+ and Er 3+ is caused by non-radiative 5 d -4 f transitions. Thermal quenching for Tm 3+ is due to ionization of 5 d electrons to conduction band. Obtained activation energy of thermal quenching of Tm 3+ 5 d -4 f luminescence is 0.66 eV. The method for the estimation of energy gap '5 d level – conduction band' is proposed.