Acoustic investigations on PbO-Al2O3-B2O3 glasses doped with certain rare earth ions

Abstract

Elastic moduli (Y, η η), Poisson's ratio (σ σ), microhardness (H) and some thermodynamical parameters such as Debye temperature (θ θ D), diffusion constant (D i), latent heat of melting (∆ ∆H m) etc of PbO-Al 2 O 3-B 2 O 3 glasses doped with rare earth ions viz. Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ and Yb 3+ , are studied as functions of temperatures (in the temperature range 30-200°C) by ultrasonic techniques. All these parameters are found to increase with increasing atomic number Z of the rare earth ions and found to decrease with increasing temperature of measurement. From these results (together with IR spectra of these glasses), an attempt is made to throw some light on the mechanical strength of these glasses. Keywords. PbO-Al 2 O 3-B 2 O 3 glasses; rare earth ions; elastic moduli.

Effect of Er2O3 and ErF3 on the structural and elastic properties of sodium oxyfluoroborate glasses

“…This may be due to the replacement of B atom by Er one to form B-O-Er linkages. In the present glass each BO 4 unit is linked to two such other units and one oxygen from each unit with a metal ion and this structure leads to formation of long chain of tetrahedral [19]. There is a weak absorption band observed at around 1650 cm À1 as seen in Fig.…”

“…This will results in lowering of the impeadence to the propagation of ultrasonic waves. Some thermodynamic parameters for the studied glasses, like the latent heat for melting, DH m , and diffusion constant D i were calculated by the relations [29],…”

Structural impact of tungsten ions on ZnO–Sb2O3–As2O3 glass system

“…The presence of common meta-centers of 2 and 3 vibrational bands of As 2 O 3 and Sb 2 O 3 in the ranges 650-668 cm −1 and 770-787 cm −1 , respectively, in the IR spectra of present glasses in fact supports the formation of such linkages. ZnO is, in general, a glass modifier and enters the glass network by breaking up the As-O-As, Sb-O-As bonds (normally the oxygens of ZnO break the local symmetries while Zn 2+ ions occupy interstitial positions) and introduces co-ordinate defects known as dangling bonds along with non-bridging oxygen ions; in this case Zn 2+ is octahedrally co-ordinated [25,26]. However, ZnO may also participate in the glass network with ZnO 4 structural units when zinc ion is linked to four oxygens in a co-valency bond configuration [27].…”

Characterization and Physical Properties of PbO–As2O3 Glasses Containing Molybdenum Ions

“…Some interesting studies on arsenic oxide glasses mixed with di!erent semiconducting oxides like GeO , SiO , V O , etc., are also available in the literature (9}12). Among di!erent As O glass systems, the alkali free, PbO}As O glasses are expected to be relatively moisture resistant and possess low rates of crystallization; PbO is, in general, a glass modi"er and enters the glass network by breaking up the As}O}As bonds (normally the oxygens of PbO break the local symmetry while Pb> ions occupy interstitial positions) and introduces coordinate defects known as dangling bonds along with non-bridging oxygen ions; in this case Pb> is octahedrally coordinated (13,14). However, PbO may also participate in the glass network with PbO structural units when lead ion is linked to four oxygens in a covalency bond con"guration.…”

“…3). The mechanical loss factor Q\ that gives the information on the mechanical strength is evaluated using standard formula (13) and its variation with the concentration of MoO is shown in the inset of Fig. 3.…”