Dr Ch Srinivasa Rao
@andhraloyolacollege.ac.in
LECTURER , DEPARTMENT OF PHYSICS
Lecturer
1. Name and full correspondence address : Dr. Ch. Srinivasa Rao
Lecturer in PHYSICS
Andhra Loyola College (Autonomous)
Vijayawada 520008
Andhra Pradesh, India
2. Email(s) and contact number(s) : drchsr1971@
+919490608071
3. Institution : Andhra Loyola College (Autonomous)
Vijayawada 520008
4. Date of Birth: 14-07-1971
5. Gender (M/F/T) : Male
EDUCATION
Ph.D. 2011 PHYSICS ACHARYA NAGARJUNA UNIVERSITY
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Materials Science, Biomaterials, Biophysics
Scopus Publications
Scopus Publications
B.K. Sudhakar, N. Rama Krishna Chand, T. Vennela, P.V.S. Sairam, G. Ravi Kumar, G. Srinivasa Rao, and Ch. Srinivasa Rao
Elsevier BV
B K Sudhakar, N Rama Krishna Chand, Vennela Tirupati, Sairam PVS, G Ravi Kumar, G Srinivasa Rao, and Ch Srinivasa Rao
IOP Publishing
Abstract Sesquioxides (Al2O3, Y2O3, Sb2O3) doped Oxy fluoro Cobalt borate novel luminescent series of glasses are prepared by melt quenching method. The structural characteristics of these glasses were studied by XRD, SEM and EDS techniques. The change in physical parameters such as density of all the series of glasses prepared gives a pathway for cobalt/Alumina/Antimony/Yttrium ions to enter in to borate glass network with the enhancement in the concentration of corresponding dopants. The depolymerization of the borate glass network is evident by the decline in various elastic parameters with B-O-Co/Y/Sb/Al bonds and by the modifier role of CoO/Y2O3/Sb2O3/Al2O3 transforming a fraction of tetrahedral BO3 units into BO4 units. Both FTIR and IR spectra indicate an increase in octahedral occupancy of cations Co2+, Y3+, Sb3+and Al3+ ions in the glass network with the increase of their concentration. The conversion rate of tetrahedral BO3 units to octahedral BO4 units leading to the formation of NBOs is more in Al3+ and least in Y3+ with the increase of concentration of sesquioxides at 0.05 mol% concentration of CoO. The optical absorption spectra of all series of glasses prepared reveal that octahedral occupancy of cobalt ions is dominant due to the ligand fields created by different sesquioxide ions in the glass network produce NBOs and number of electrons trapped at the donor centers. The PL spectra of all the series of these glasses reveal the octahedral occupancy of Co2+ ions, which is evident from the two emission transitions 2T1g(H) →4T1g(F) (531–556 nm) and 2Eg→5T2g (699–718 nm).The prepared series of glasses show efficient luminescence of Cobalt ions, and Al2O3 series of glasses are better candidates for luminescence as their emission Cross-sections are highest when compared with the remaining series of glasses.
N. Rama Krishna Chand, B.K. Sudhakar, T. Vennela, P.V.S. Sairam, G. Ravikumar, G. Srinivasa Rao, and Ch. Srinivasa Rao
Elsevier BV
N. Rama Krishna Chand, B.K. Sudhakar, G. Ravikumar, V. Gayathri, P. Devika, T. Vennela, G. Srinivasa Rao, and Ch.Srinivasa Rao
Elsevier BV
N Rama Krishna Chand, B K Sudhakar, G Ravikumar, G Srinivasa Rao, and Ch Srinivasa Rao
IOP Publishing
The glass system 20CaF2-20ZnO-(60-x)P2O5:xMnO with 0 ≤ x ≤ 5.0 was prepared and investigated. The structural changes induced by the addition of MnO in the glass network were explained by using physical, elastic, thermal, chemical durability and spectroscopic studies. Results indicate that with the increase of concentration of MnO content from 1 to 5 mol% the parameters like density, pH of the immersion liquid, elastic moduli and glass characteristic temperatures increases. While the dissociation rate, the Poisson’s ratio and volume per mol decreases and signifying the increased mechanical strength of the prepared glasses. FTIR spectral analysis predicts that all the specific vibrational bands of phosphate bonds like bridging oxygen with phosphorous action, linkages like P-O-P, O-P-O and the crossed linkages like P-O-Mn & P-O-Zn are affected by the incorporation of MnO in the glass matrix. The changes observed in peak positions and intensities of all vibrational bands of IR spectra and optical absorption spectra confirm that manganese ions behaves as a glass former and also as a glass modifier depending on the concentration of MnO. The analysis of the optical absorption spectra of the glasses in particular the crystal field and interelectronic repulsion parameters shows that manganese ions are predominantly occur in the divalent state and occupy tetrahedral sites in the glass matrix when the concentration of MnO in the CaF2-ZnO-P2O5 glasses exceeds 1.0 mol%.
G. Anil Kumar, Y. Rambabu, Ravi Kumar Guntu, K. Sivaram, M. Sreenath Reddy, Ch. Srinivasa Rao, V. Venkatramu, V. Ravi Kumar, and N. Ch. Sriman Narayana Iyengar
Elsevier BV
Ravi Kumar Guntu, N. Jahangeer, and Ch. Srinivasa Rao
Springer Science and Business Media LLC
Ravi Kumar Guntu, V. Venkatramu, Ch. Srinivasa Rao, and V. Ravi Kumar
Elsevier BV
G Ravi Kumar and Ch Srinivasa Rao
Springer Science and Business Media LLC
Padala Ashok, Ravi Kumar Guntu, G. Bhikshamaiah, Y. Markandeya, M. Madhu, Kore Anusha, N. Jahangeer, G. Anil Kumar, N. Ch. Sriman Narayana Iyengar, and Ch. Srinivasa Rao
Elsevier BV
Ravi kumar Guntu, Y. Rambabu, T. Srikumar, and Ch Srinivasa Rao
Elsevier BV
G. Ravi Kumar, T. Srikumar, G. Murali Krishna, G. Sahaya Baskaran, A. Siva Sesha Reddy, V. Ravi Kumar, and Ch. Srinivasa Rao
Elsevier BV
G. Jagan Mohini, N. Krishnamacharyulu, G. Sahaya Baskaran, Ch. Srinivasa Rao, V. Ravi Kumar, and N. Veeraiah
Elsevier BV
G. Ravi Kumar, Ch. Srinivasa Rao, and M.C. Rao
Elsevier BV
M. C. Rao, T. Srikumar, D. V. Satish, J. Siva Rama Krishna, Ch. Srinivasa Rao, and Ch. Ranga Rao
Author(s)
Zinc Stannate (ZnSnO3) doped nanocomposite polymer electrolyte films have been prepared with the composition PVA-CH3COONa by solution cast technique. The prepared samples were characterized by XRD. Further, humidity sensing parameters were studied on the prepared nanocomposite film. XRD revealed that the prepared nano-composite film has a perovskite phase with orthorhombic structure. From the humidity sensing parameters, the prepared compositional ratio of nanocomposite film exhibited better performance and the maximum sensitivity of the sample was found to be 3 GΩ/% RH.
G. Ravi Kumar, M. Koteswara Rao, T. Srikumar, M.C. Rao, V. Ravi Kumar, N. Veeraiah, and Ch.Srinivasa Rao
Elsevier BV
G. Ravi Kumar, T. Srikumar, M.C. Rao, P. Venkat Reddy, and Ch. Srinivasa Rao
Elsevier BV
T. Subrahmanyam, K. Rama Gopal, R. Padma Suvarna, B. Chinna Jamalaiah, and Ch Srinivasa Rao
Elsevier BV
G Ravi Kumar, T Srikumar, M C Rao, P Venkat Reddy, and Ch Srinivasa Rao
IOP Publishing
Glasses with compositions (20–x) LiF–10 Sb2O3–10 B2O3–60 P2O5: x CoO (0 < x < 0.25) were synthesized by conventional rapid melt quenching method. The non–crystalline nature of the samples was confirmed by XRD analysis and the glass forming abilities were analyzed by DTA studies. The compositional dependence of various structural vibrational units was analyzed by FT–IR and Raman studies. The DTA, FT–IR and Raman studies suggested a higher degree of disorder in the glass network with increasing concentration of CoO up to 0.15 mol%. The reversal trend has been observed beyond 0.15 mol% suggesting an increasing polymerization of glass network. The optical properties of LiF–Sb2O3–B2O3–P2O5: CoO glasses were analyzed by optical absorption and photoluminescence studies. The observations from OA and PL spectral studies suggested that the gradual increase of octahedral Co2+ ions with the increase in the concentration of CoO up to 0.15 mol%. At higher concentration i.e. above 0.15 mol% of CoO, there was a reduction in the concentration of octahedral Co2+ ions. The electrical properties of the glass samples were studied by both DC and AC conductivity studies. The dielectric dispersion analysis was also performed on the prepared glass samples. The results of these studies indicated that there is a mixed conduction (both ionic and polaronic) and the polaron hoping seems to prevail over ionic conduction in the glasses containing CoO less than 0.15 mol%. The increasing space charge polarization is responsible for enhanced values of dielectric constant, dielectric loss and AC conductivity for all frequency and temperature ranges with the increase in concentration of CoO up to 0.15 mol%.
T. Srikumar, Ch. Srinivasa Rao, M.C. Rao, R. Raja Priyanka, T. Vennela, J. Saidurga, and B. Karthik
Elsevier BV
Ch. Srinivasa Rao, K. Seshulatha, Y.S. Gurupria, Prem Sagar, M. VijayKumar, S. SaibabaVali, D. Ramanjaneyulu, and S. Kotireddy
Elsevier BV
K. Bhargavi, M. Sundara Rao, Ch. Srinivasa Rao, and Y. Gandhi
Elsevier BV
M.C. Rao, Ch. Srinivasa Rao, and T. Srikumar
Elsevier BV
M. Tanooj Kumar, K. S. Srikanth, Ch. Ranga Rao, K. Ramachandra Rao, Ch. Srinivasa Rao, and M. C. Rao
Author(s)