Structural and optical properties of TiO₂ thin films derived by sol-gel dip coating process

Saini, K.K.,Sharma, S.D.,Chanderkant,Kar, M.,Singh, D.,Sharma, C.P. North-Holland 2007 Journal of non-crystalline solids Vol.353 No.24

Nanocrystalline thin films of titanium dioxide have been fabricated on glass and silica substrates from partially hydrolyzed precursor solution. These films were subjected to heat treatment for 1h at temperatures 100, 200, 300, 400, 500, 600, 700, 800 and 900<SUP>o</SUP>C and characterized by XRD, SEM, XPS and optical techniques. As deposited films are found to be amorphous and also contain hydroxyl and organic functional groups. Films heat treated above 100<SUP>o</SUP>C do not contain hydroxyl and organic functional groups. Microcrystalline behavior is observed in the films heat treated above 300<SUP>o</SUP>C. Crystallite size increases from ∼5 to 50nm as sintering temperature is increased from 300 to 700<SUP>o</SUP>C. Formation of anatase phase with c-axis length 7.03A is observed in the films annealed up to 700<SUP>o</SUP>C. These films peel off from the substrate beyond 700<SUP>o</SUP>C annealing temperature. Density as well as refractive index of the films increases with increase in annealing temperature up to 700<SUP>o</SUP>C. Refractive index is found to show Cauchys behavior. Transmission better than 70% is observed in the visible range. There is a strong absorption around 370nm, which is attributed to band gap absorption of the material.

Principal Component Analysis and Molecular Characterization of Reniform Nematode Populations in Alabama

Seloame T. Nyaku,Ramesh V. Kantety,Ernst Cebert,Kathy S. Lawrence,Joseph O. Honger,Govind C. Sharma 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.2

U.S. cotton production is suffering from the yield losscaused by the reniform nematode (RN), Rotylenchulusreniformis. Management of this devastating pest is ofutmost importance because, no upland cotton cultivarexhibits adequate resistance to RN. Nine populationsof RN from distinct regions in Alabama and onepopulation from Mississippi were studied and thirteenmorphometric features were measured on 20 male and20 female nematodes from each population. Highly correlatedvariables (positive) in female and male RN morphometricparameters were observed for body length(L) and distance of vulva from the lip region (V) (r = 0.7)and tail length (TL) and c’ (r = 0.8), respectively. Thefirst and second principal components for the femaleand male populations showed distinct clustering intothree groups. These results show pattern of sub-groupswithin the RN populations in Alabama. A one-wayANOVA on female and male RN populations showedsignificant differences (p ≤ 0.05) among the variables.Multiple sequence alignment (MSA) of 18S rRNA sequences(421) showed lengths of 653 bp. Sites within thealigned sequences were conserved (53%), parsimonyinformative(17%), singletons (28%), and indels (2%),respectively. Neighbor-Joining analysis showed intraand inter-nematodal variations within the populationsas clone sequences from different nematodes irrespectiveof the sex of nematode isolate clustered together. Morphologically, the three groups (I, II and III) couldnot be distinctly associated with the molecular datafrom the 18S rRNA sequences. The three groups maybe identified as being non-geographically contiguous.

Influence of growth temperature and post-annealing on an n-ZnO/p-GaN heterojunction diode

Sharma, S.K.,Heo, S.,Lee, B.,Lee, H.,Kim, C.,Kim, D.Y. Elsevier 2014 CURRENT APPLIED PHYSICS Vol.14 No.12

We report on an n-ZnO/p-GaN heterojunction diode fabricated from zinc oxide (ZnO) films at various growth temperatures (450, 500, 550, and 600 <SUP>o</SUP>C) by RF sputtering. The films were subsequently annealed at 700 <SUP>o</SUP>C in N<SUB>2</SUB> ambient. To investigate the influence of the growth temperature of n-ZnO films, the microstructural, optical, and electrical properties were measured using scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL), and Hall measurements. The XRD pattern showed the preferred orientation along the c-axis (002) regardless of growth temperature. The PL spectra showed a dominant sharp near-band-edge (NBE) emission. Current-voltage (I-V) curves showed excellent rectification behavior. The turn-on voltage of the diode was observed to be 3.2 V for the films produced at 500 <SUP>o</SUP>C. The ideality factor of ZnO film was observed to be 1.37, which showed the best performance of the diode.

Tourism in Maldives

S,C,Bagri,S,K,Gupta,Reena Sharma 세계문화관광학회 2009 Conference Proceedings Vol.10 No.0

The paper includes the growth of tourism since years in Maldives. The paper examines tourist development in Maldives. This will include the tourism indicators and impacts of tourism economically, socially and culturally. Although social/cultural impacts from coastal tourism development have been widely recognized in a great number of cases, it is relatively, difficult to develop technical criteria, for evaluating these impacts in quantitative terms. According to the Ministry of Tourism website, the emergence of tourism in 1972 transformed the economy of the Maldives, moving rapidly from the dependence on the fisheries sector to the tourism sector. Just in three and a half decades, the industry has become the main source of income and livelihood of the people of the Maldives. Tourism is also the country's biggest foreign currency earner and the single largest contributor to the GDP. Today, there are 89 resorts in the Maldives with a bed capacity of over 17,000, providing world class facilities for tourists whose annual arrival figure exceeds 600,000.

Principal Component Analysis and Molecular Characterization of Reniform Nematode Populations in Alabama

Nyaku, Seloame T.,Kantety, Ramesh V.,Cebert, Ernst,Lawrence, Kathy S.,Honger, Joseph O.,Sharma, Govind C. The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.2

U.S. cotton production is suffering from the yield loss caused by the reniform nematode (RN), Rotylenchulus reniformis. Management of this devastating pest is of utmost importance because, no upland cotton cultivar exhibits adequate resistance to RN. Nine populations of RN from distinct regions in Alabama and one population from Mississippi were studied and thirteen morphometric features were measured on 20 male and 20 female nematodes from each population. Highly correlated variables (positive) in female and male RN morphometric parameters were observed for body length (L) and distance of vulva from the lip region (V) (r = 0.7) and tail length (TL) and c' (r = 0.8), respectively. The first and second principal components for the female and male populations showed distinct clustering into three groups. These results show pattern of sub-groups within the RN populations in Alabama. A one-way ANOVA on female and male RN populations showed significant differences ($p{\leq}0.05$) among the variables. Multiple sequence alignment (MSA) of 18S rRNA sequences (421) showed lengths of 653 bp. Sites within the aligned sequences were conserved (53%), parsimony-informative (17%), singletons (28%), and indels (2%), respectively. Neighbor-Joining analysis showed intra and inter-nematodal variations within the populations as clone sequences from different nematodes irrespective of the sex of nematode isolate clustered together. Morphologically, the three groups (I, II and III) could not be distinctly associated with the molecular data from the 18S rRNA sequences. The three groups may be identified as being non-geographically contiguous.

Fabrication of the flexible nanogenerator from BTO nanopowders on graphene coated PMMA substrates by sol-gel method

Sankar Ganesh, R.,Sharma, Sanjeev K.,Abinnas, N.,Durgadevi, E.,Raji, P.,Ponnusamy, S.,Muthamizhchelvan, C.,Hayakawa, Y.,Kim, Deuk Young Elsevier Sequoia S.A 2017 Materials chemistry and physics Vol.192 No.-

<P><B>Abstract</B></P> <P>Nanostructured bismuth titanate (Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB>) or BTO powders were synthesized by the combustion method. The crystalline phase of BTO nanopowders was evaluated from X-ray diffraction (XRD) and further confirmed by selected area electron diffraction (SAED) pattern. The SEM and TEM micrographic images clearly showed the nanosheets like morphology of BTO nanopowder. The EDS spectrum of BTO nanopowder showed the elemental peaks of O, Bi and Ti at 0.53 keV, 2.41 keV and 4.49 keV, respectively. FTIR band peaks were observed at 815 and 595 cm<SUP>−1</SUP> corresponding to the stretching vibrations of BiO and TiO. The red shift in optical absorption of BTO was observed and the bandgap decreased from 3.18 to 3.08 eV as the calcined temperature increased from 600 to 800 °C. The sandwich structure, called the nanogenerator, Graphene/BTO-PDMS/Graphene (G/BTO/G), was fabricated on graphene coated polymethyl methacrylate (PMMA) substrates, which produced a peak voltage (10 mV) by applying the pressure from human's finger. The switching mechanism of BTO nanosheets was observed to be dependent on the polarity and intrinsic dipole formation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> (BTO) nanosheets synthesized from a simple combustion method. </LI> <LI> SEM & TEM images confirmed the nanosheets structure with a hexagonal shape. </LI> <LI> XRD and SAED pattern of BTO nanosheets confirmed the orthorhombic crystal structure. </LI> <LI> Flexible G/BTO/G nanogenerator fabricated by sol-gel method. </LI> <LI> Peak voltage was observed to be 10 mV by applying pressure from human's finger. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Microstructure, structural, optical and piezoelectric properties of BiFeO₃ nanopowder synthesized from sol-gel

Sankar Ganesh, R.,Sharma, S.K.,Sankar, S.,Divyapriya, B.,Durgadevi, E.,Raji, P.,Ponnusamy, S.,Muthamizhchelvan, C.,Hayakawa, Y.,Kim, D.Y. ELSEVIER 2017 Current Applied Physics Vol.17 No.3

<P>Nanocrystalline BiFeO3 (BFO) powder was synthesized by sol-gel method and subsequent annealed at 100-500 degrees C. The microstructural analysis of BFO nanopowder confirmed the perovskite like structure of spherical nanoparticles annealed at 500 degrees C. The Raman spectrum of BFO nanoparticles showed the rhombohedrally structure with the space group of R3c. The XPS spectrum of BFO nanopowder showed the peaks of Bi, Fe, and O at the binding energy of 158.8, 711.75 and 529.2 eV, respectively. The piezoelectric properties of BFO nanoparticles were evaluated by making the sandwiched structure of graphene/BiFeO3-PDMS/graphene. The fabricated piezoelectric device demonstrated an output voltage of 0.4 V by applying the normal pressure from human finger on the device. (C) 2016 Elsevier B.V. All rights reserved.</P>

Microstructure, structural, optical and piezoelectric properties of BiFeO3 nanopowder synthesized from sol-gel

R. Sankar Ganesh,Sanjeev K. Sharma,S. Sankar,B. Divyapriya,E. Durgadevi,P. Raji,S. Ponnusamy,C. Muthamizhchelvan,Y. Hayakawa,김득영 한국물리학회 2017 Current Applied Physics Vol.17 No.3

Nanocrystalline BiFeO3 (BFO) powder was synthesized by sol-gel method and subsequent annealed at 100e500 C. The microstructural analysis of BFO nanopowder confirmed the perovskite like structure of spherical nanoparticles annealed at 500 C. The Raman spectrum of BFO nanoparticles showed the rhombohedrally structure with the space group of R3c. The XPS spectrum of BFO nanopowder showed the peaks of Bi, Fe, and O at the binding energy of 158.8, 711.75 and 529.2 eV, respectively. The piezoelectric properties of BFO nanoparticles were evaluated by making the sandwiched structure of graphene/ BiFeO3-PDMS/graphene. The fabricated piezoelectric device demonstrated an output voltage of 0.4 V by applying the normal pressure from human finger on the device.

Room-temperature relaxor ferroelectricity and photovoltaic effects in tin titanate directly deposited on a silicon substrate

Agarwal, Radhe,Sharma, Yogesh,Chang, Siliang,Pitike, Krishna C.,Sohn, Changhee,Nakhmanson, Serge M.,Takoudis, Christos G.,Lee, Ho Nyung,Tonelli, Rachel,Gardner, Jonathan,Scott, James F.,Katiyar, Ram S American Physical Society 2018 Physical review. B Vol.97 No.5

<P>Tin titanate (SnTiO3) has been notoriously impossible to prepare as a thin-film ferroelectric, probably because high-temperature annealing converts much of the Sn2+ to Sn4+. In the present paper, we show two things: first, perovskite phase SnTiO3 can be prepared by atomic-layer deposition directly onto p-type Si substrates; and second, these films exhibit ferroelectric switching at room temperature, with p-type Si acting as electrodes. X-ray diffraction measurements reveal that the film is single-phase, preferred-orientation ferroelectric perovskite SnTiO3. Our films showed well-saturated, square, and repeatable hysteresis loops of around 3 mu C/cm(2) remnant polarization at room temperature, as detected by out-of-plane polarization versus electric field and field cycling measurements. Furthermore, photovoltaic and photoferroelectricity were found in Pt/SnTiO3/Si/SnTiO3/Pt heterostructures, the properties of which can be tuned through band-gap engineering by strain according to first-principles calculations. This is a lead-free room-temperature ferroelectric oxide of potential device application.</P>

Effect of Varying Levels of Dietary Minerals on Growth and Nutrient Utilization in Lambs

Sharma, L.C.,Yadav, P.S.,Mandal, A.B.,Sunaria, K.R. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.1

Hisardale male lambs (n=24, 4-5 month of age) were maintained on a conventional ration for a month, to equilibrate the body mineral status. Six lambs were sacrificed after one month of feeding; the samples of organs were analyzed to ascertain mineral status. The remaining 18 lambs were divided into 3 groups of 6 each on body weight basis. Three dietary treatments containing 100 ($T_1$), 110 ($T_2$) and 120% ($T_3$) of minerals (Ca, P, S, Zn and Mn) as specified by NRC (1985) were formulated and each treatment was alloted ad libitum to a group for 120 days. Blood and wool samples were collected at monthly intervals. At the end of the experiment a balance trial of 5 days duration was conducted to study the balance of mineral elements. The effective intake of minerals was Ca, 111 and 120, P, 110 and 122; S, 112 and 129; Zn, 112 and 126 and Mn, 109 and 123 percent in $T_2$ and $T_3$, respectively, in comparison to $T_1$ (100). The additional mineral supplementation had no significant effect on dry matter intake. The average daily weight gain was higher (p<0.01) in $T_2$ and $T_3$ than the control ($T_1$). The lambs under treatments $T_2$ (8.72) and $T_3$ (8.47 kg) consumed apparently lesser amount of dry matter per unit gain as compared to $T_1$ (10.81 kg). Significantly higher (p<0.05) dry matter and crude protein digestibility (%) were observed in $T_2$ and $T_3$ than in $T_1$. The mean balances for different elements were Ca, 1.14, 1.68 and 1.67 g; P, 1.70, 1.95 and 2.18 g; S, 0.54, 0.92 and 1.11 g; Zn, 22.56, 25.30 and 28.71 mg; Cu, 7.94, 5.71 and 5.53 mg; Fe, 33.19, 32.94 and 31.03 mg and Mn, 8.24, 14.40 and 16.07 mg/lamb/day. The retention of supplemental minerals increased (p<0.01) while that of Cu decreased (p<0.01) due to supplementation of minerals (Ca, P, S, Zn and Mn). Retention as per cent of intake increased statistically for S and Mn while that of Cu decreased. It can be concluded that supplementation of minerals (Ca, P, S, Zn and Mn) higher than the recommended level improved body weight gain and feed to gain ratio. The retention of minerals increased due to supplementation. Therefore, an additional supplementation of deficient minerals (Ca, P, S, Zn and Mn) by 10% was beneficial for Hisardale male lambs under tropical condition in India.