Spectroscopic characterization of manganese-doped alkaline earth lead zinc phosphate glasses

Abstract

Alkaline earth lead zinc phosphate glasses doped with Mn(II) are characterized by spectroscopic techniques like X-ray diffraction (XRD), UV-visible, differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR), Fourier transform infrared (FTIR) and Raman. Optical absorption spectrum exhibits four bands which are characteristic of Mn(II) in distorted octahedral site symmetry. The crystal field parameter Dq and Racah interelectronic-repulsion parameters B and C have been evaluated. All investigated samples exhibit EPR signals which are characteristic to the Mn 2+ ions. The shapes of spectra are also changed with varying alkaline earth ions content. FTIR spectra show specific vibrations of phosphate units. The characteristic Raman bands of these glasses due to stretching and bending vibrations were identified and analysed by varying alkaline earth content. The intensity and frequency variations for the characteristic phosphate group vibrations have been correlated with the changes of the structural units present in these glasses. Depolymerization of the phosphate chains in all the glasses is observed with replacement of alkaline earth content by spectroscopic studies. This leads to a strong decrease of the average chain length and a small decrease of the average P-O-P bridging angle with replacement of alkaline earth content.

Structural and emission properties of Eu3+‐doped alkaline earth zinc‐phosphate glasses for white LED applications

“…The FT‐IR spectra for the prepared glasses ZPMT1, ZPCT1, ZPST1, and ZPBT1 are represented in Figure in the range 400‐1500 cm −1 . The band present in the range 450‐650 cm −1 may be ascribed to the Zn–O tetrahedral bonds . The presence of ZnO tetrahedral bonds indicates that the ZnO enters the glass structure as a former.…”

“…The absorption peaks centered at band 748 and 925 cm −1 are attributed to the symmetric stretching, ʋ s (PO 2 ), and antisymmetric stretching, ʋ as (PO 2 ), of the P–O–P linkages of the bridging oxygen atoms bonded to the phosphorous, respectively . The simultaneous occurrence of bands present at 748 and 925 cm −1 indicate the presence of pyrophosphate structure (P 2 O 7 ) 4− . The band in the region 800‐1400 cm −1 is broad, and this band consists of several peaks.…”

“…All these values of T g , T p1 , T p2 , T x 1 , and T x 2 are given in Table . The network modifiers directly influence the T g because glass transition involves modification of chemical bonds between the glass former and glass modifiers . The value of T g was maximum for the ZPBT1 followed by ZPST1, ZPCT1, and ZPMT1 glasses, which indicates that the higher field strength cations (Ba 2+ >Sr 2+ >Ca 2+ >Mg 2+ ) create a more tightly bonded glass structure .…”

Influence of Various Glass Compositions on Physical and Spectroscopic Properties of Cao-Pb3O4-Zno-P2O5 Glass System

“…P-O-P asymmetric stretching vibration mode is assigned to 750 cm -1 band position, a shoulder at ~ 910 cm -1 and a band at ~ 1020 cm -1 which is appropriate to assign to the P-O stretching modes 29,31]. The band at ~1100cm -1 is due to ( s ( PO 2 ) -) mode [32], the bands at 1140 cm -1 and 1170 cm -1 are attributed to (P-O) -stretch and (PO 2 ) sym stretch, Q 2 units [33]. The characteristic bands of PbO appear at low frequencies (330-340 cm -1 ).…”

Characterization and Optical Properties of MnO Doped CuO-Containing Phosphate Glass as Absorption Filters

“…Phosphate-based glasses doped with manganese are interesting due to their structural properties and their coordination [23,24]. It turns out that manganese ions can be utilized as a paramagnetic tool to study the structure and properties of glassy systems, due to the strong influence of manganese ions on optical and magnetic properties of glass [25].…”