Y4Al2O9 (YAM) Al-oxide or alumina is a technologically important material for many optical, electronic, mechanical and nuclear applications. Because, it offers excellent mechanical properties, good chemical stability, high temperature (2020 ℃), denseness (4.44 g/cm3 ), low high-temperature thermal physical phenomenon and low permeability to rare earth impurity. High Injury tolerant ability, that endure it as a prospective material for thermal and/or environmental barrier coating applications [1-4]. Therefore, it is a promising host material for rare earth ions to produce efficient luminescent media, previous theoretical and experimental investigations have incontestable applications, it's necessary to systematically investigate the structural, optical, thermal, and mechanical properties of YAM. In addition, significant energy transferring from the host material to the RE element is an efficient solution to circumvent the suppressed absorptions of RE ions with the 4f–4f transitions. As a matter of fact, a large range of wavelengths can be emitted from these phosphors because remarkable luminescence quantum yields can be achieved for the f-f transitions [2,5]. The TL properties of Y4Al2O9 (YAM) samples of different dopant materials, which can enhance TL properties, have been studied by several researchers for several decades [5, 6]. Moreover, modification of alumina with transitions and semiconductor elements such as chromium and silicon oxides is expected to increase the number of defects in alumina structure and improve its absorption ability [5-8]. In this work, the role of Gd as dopant introduced in YAM phosphor a nanostructure, prepared by the solid state reaction method, will be explored in details. Various investigations of such newly prepared samples have been carried out leading to great benefit of having an enhanced radiation-dosimetry system through TL studies and optical studies such as PL. The prepared phosphor sample was characterized using XRD for structural characterization.