Thermo, Photo and Mechanoluminescence Studies of Eu3+ Doped Y4Al2O9 Phosphors: TL, PL, and ML Analysis of YAM: Eu3+

Introduction

During the past decades, nanostructured materials have attracted considerable attention for their novel and enhanced properties, e.g., the Mn doped ZnS phosphor can yield both high luminescent efficiencies and short lifetime Bhargava et al. (1994) and Zhang et al. (1998). Nanostructured materials may be developed to form a novel type of luminescent materials for display applications.

The Y₂O₃–Al₂O₃ system is a promising material for refractory coatings and for ceramic and semiconductor processing technology Lo et al. (1998) and Aguilar et al. (2000). Doped yttrium aluminium garnet (YAG) is widely used as a laser host material Lupei et al. (2002) and Vodopyanov et al. (1998), and yttrium aluminumperovskite (YAP) used as scintillation host material Glodo et al. (2000). In addition, rare earth doped YAG is also employed as a phosphor Lu et al. (2002) and Choe et al. (2001). However, there are few reports on rare earth doped Y₄Al₂O₉ (YAM). It has been reported that the space group for the crystal structure of Y₄Al₂O₉ is P2₁/c of monoclinic Yamane et al. (1998 a & b). The Al atoms are coordinated to four oxygen atoms, the Y atoms are coordinated to either six or seven oxygen atoms Yamane et al. (1998 a & b), and its site symmetry is C1 Rabinovitch et al. (2004). There are four formula units in the unit cell of the room temperature phase of Y₄Al₂O₉ and four different rare earth sites in the asymmetric unit. Xia et al. (2005) have synthesized the Y₄Al₂O₉:Eu³⁺ phosphor through a sol–gel combustion method, where the Y₄Al₂O₉ phase can form through sintering at 800 ⁰C. However, higher doping concentration could be realized in Y₄Al₂O₉:Eu³⁺nano-crystal host lattice. Shengli Liu et al. have also prepared the Y₄Al₂O₉:(Tb³⁺, Eu³⁺) by sol–gel process Shengli and Su (1997) Wang et al. (2006), Kaur et al. (2012) and Dubey et al. (2013) have studied the VUV excitation and photoluminescence characteristics of this Y_3.8Al₂O₉:Re_0.2 (Re = Tb³⁺, Eu³⁺) phosphor synthesized via a citric-gel method. This phosphor shows strong absorption in VUV region. The results indicate that this phosphor could be one of the potential candidates for PDPs applications.