• P MURUGAKOOTHAN

Articles written in Bulletin of Materials Science

• Superconductivity and morphological studies on Bi2Sr2CaCu2O8 single crystals grown from stoichiometric and nonstoichiometric melts

Single crystals of Bi2Sr2CaCu2O8 (2212) have been grown by self-flux technique using stoichiometric and non-stoichiometric melts of excess CuO and Bi2O3. Single-crystal and powder X-ray diffraction studies have been made on the grown crystals to confirm their single crystallinity and structure respectively. Resistivity and susceptibility measurements provide information on the superconducting nature of the crystals. The effects of fluxing agents and starting composition on surface morphology and superconducting properties have been discussed.

• Synthesis and characterization of Znq2 and Znq2:CTAB particles for optical applications

High luminescent zinc (ii)-bis (8-hydroxyquinoline) Znq2 nanoparticles were synthesized by the simpleprecipitation method in pure form and with cetyltrimethyl ammonium bromide (CTAB) as cationic surfactant. The crystallinenature of title samples was confirmed by powder X-ray diffraction. Thermo gravimetric analysis and differential thermal analysis were carried out to find the thermal stability of the synthesized samples. The morphology and elemental analyses of the samples were studied by scanning electron microscope and energy dispersive X-ray analyser, respectively. The functional groups of these nanoparticles were analysed and assigned using the Fourier transform infrared spectroscopy spectral study. The optical property of Znq2 and Znq2:CTAB was confirmed by UV–vis–NIR spectral study. The band gap of Znq2 was calculated. The synthesized Znq2 and Znq2:CTAB nanoparticles were confirmed by photoluminescence studies for organic-light-emitting diode applications as emission and electron transport layers.

• Discussion on growth, emission and piezoelectric properties of zinc guanidinium phosphate single crystal: a potential candidate for transducer and LED applications

Zinc guanidinium phosphate, a semi-organic single crystal, was grown successfully by a slow evaporation solution growth technique. The cell parameters of the grown crystal were confirmed using a powder X-ray diffractionstudy. The electrical property of the sample was analysed using dielectric and piezoelectric studies. The dielectric constant, dielectric loss and alternating-current conductivity were calculated for various frequencies and temperatures. The solid state parameters such as plasma energy, Penn gap energy, Fermi energy and electronic polarizability were calculated. The piezoelectric property of the title crystal was ascertained by determining its piezoelectric charge coefficient ($d_{33}$). The optical transmittance and energy gap of the grown crystal were examined using ultraviolet–visible–near-infrared spectral analysis.The title molecule was optimized and the frontier molecular orbital was performed using B3LYP/6-31 $+$ G(2d,2p). The emission property of the titular compound was analysed using a photoluminescence study. The dominant colour emission ofthe grown crystal was found using CIE colour chromaticity coordinates. The nonlinear property of the titular compound was confirmed using a Kurtz–Perry powder technique. The above results illustrate that the title crystal is a potential candidate for light emitting and nonlinear applications. This work explains the dominant colour emitting behaviour and electrical properties such as dielectric and piezoelectric properties of the title crystal, which are reported for the first time.

• # Bulletin of Materials Science

Volume 44, 2021
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020