Structural Study through Magnetic and Spectroscopic Properties on ...

F 4 423 583 880 160 297 0.539
F 5 426 597 895 171 298 0.574
F 6 422 583 891 161 308 0.523
F 7 418 581 896 163 315 0.517
Vol.2, No.2-3, 83-91(2011)
Table-3: Summary of the data on b<strong>and</strong> positions (cm −1 ) of various absorption b<strong>and</strong>s in the IR spectra of PbO-TiO 2 -
B 2 O 3 : Fe 2 O 3 glasses
Glass
BO 3
(cm -1 )
Borate groups
BO 4
(cm -1 )
B-O-B
(cm -1 )
B<strong>and</strong> due to TiO 4
(cm -1 )
B<strong>and</strong>
due to
Ti-O-Ti
(cm -1 )
B<strong>and</strong> due to
PbO 4 units
(cm -1 )
F 0 1362 1038 723 723 650 480
F 1 1367 1035 723 723 650 480
F 2 1373 1031 723 723 650 480
F 3 1383 1030 723 723 650 480
F 4 1393 1023 723 723 650 480
F 5 1398 1021 723 723 650 480
F 6 1386 1033 723 723 650 480
F 7 1360 1058 723 723 650 480
Table-4: Summary of data on optical absorption spectra of PbO-TiO 2 -B 2 O 3 : Fe 2 O 3 glasses
Transition
Glass Sample
F 0 F 1 F 2 F 3 F 4 F 5 F 6 F 7
Fe 3+ transitions (nm)
A 1 (t 3 2g e 2 g) →a 4 T 1 (t 4 2g e g ) -- 540 540 540 540 540 540 540
6 A 1 (t 3 2g e 2 g) →a 4 T 2 (t 4 2g e g ) -- 580 580 580 580 580 580 580
6 A 1 (t 3 2g e 2 g) →a 4 T 1 (e 3 t 2 2) -- 787 787 787 787 787 787 787
Fe 2+ transition (nm)
5 T 2g → 5 E g -- 955 955 955 955 955 955 955
Cut-off wavelength (nm) 401 391 389 386 383.1 378 393 396
Optical b<strong>and</strong> gap (eV) -- 2.32 2.4 2.47 2.5 2.65 2.25 2.20
Table-5: Data on magnetic properties of PbO-TiO 2 -B 2 O 3 : Fe 2 O 3 glasses
Glass Conc. of Fe 2 O 3 (mol %) Susceptibility, χ (10 -5 , emu) µ (µ B )
F 1 0.1 12.32 5.2
F 2 0.2 13.56 5.3
F 3 0.3 14.25 5.4
F 4 0.4 19.24 5.5
F 5 0.5 21.56 5.8
F 6 0.6 7.25 4.7
F 7 0.7 3.61 4.6
The observed values of T g , T c <strong>and</strong> T m , the parameters (T c -T g ), (T m -T c ) <strong>and</strong> glass forming ability parameter
known as Hruby’s parameter, K gl = (T c -T g )/(T m -T c ) are evaluated <strong>and</strong> presented in Table 2. The disparity of the
86
T.V. Nagalakshmi et al.