Nanoparticles of cadmium selenide (CdSe) and Fe (5% and 10%) doped CdSe have been synthesized by soft chemical route and found to have cubic structure. The magnetic field dependent magnetization measurement of the doped samples indicates the presence of anti-ferromagnetic order. The temperature dependent magnetization (M-T) measurement under zero field cooled and field cooled conditions has also ruled out the presence of ferromagnetic component in the samples at room temperature as well as low temperature. In order to estimate the anti-ferromagnetic coupling among the doped Fe atoms, an M-T measurement at 500 Oe has been carried out, and the Curie-Weiss temperature θ of the samples has been estimated from the inverse of susceptibility versus temperature plots. The dielectric relaxation peaks are observed in the spectra of imaginary part of dielectric constant. The temperature dependent relaxation time is found to obey the Arrhenius law having activation energy ~ 0.4 eV for Fe doped samples. The frequency dependent conductivity spectra are found to obey the power law. © 2018, The Korean Institute of Metals and Materials and Springer Science+Business Media B.V.

SOURISH BANERJEE

Physics

SUDIPTA BANDYOPADHYAY

S DAS

T P SINHA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Electronic Materials Letters

Nanoparticles of cadmium oxide have been synthesized by soft chemical route using thioglycerol as the capping agent. The crystallite size is determined by X-ray diffraction technique and the particle size is obtained by transmission electron microscope. The band gap of the material is obtained using Tauc relation to UV–visible absorption spectrum. The photoluminescence emission spectra of the sample are measured at various excitation wavelengths. The molecular components in the material have been analyzed by FT-IR spectroscopy. The dielectric dispersion of the material is investigated in the temperature range from 313 to 393 K and in the frequency range from 100 Hz to 1 MHz by impedance spectroscopy. The Cole–Cole model is used to describe the dielectric relaxation of the system. The scaling behavior of imaginary part of impedance shows that the relaxation describes the same mechanism at various temperatures. The frequency-dependent electrical data are also analyzed in the framework of conductivity and electrical modulus formalisms. The frequency-dependent conductivity spectra are found to obey the power law. © 2015, The Author(s).

Fulltext

Applied Nanoscience (Switzerland)

Dielectric relaxation of CdO nanoparticles

Nanoparticles of pure and iron (5% and 10%) doped cadmium selenide (CdSe) have been synthesized by soft chemical route and are found to have cubic structure. EDAX analysis supports the inclusion of Fe into CdSe nanoparticles. The average particle size of pure and doped CdSe is found to be ~5 nm. The band gap of the materials is obtained using Tauc relation to UV-visible spectra and found to be about 2.23, 2.14 and 2.1 eV respectively for pure and Fe (5% and 10%) doped CdSe. The observed peaks at 546 nm and 436 nm in the photoluminescence spectra of the samples correspond to 1s-1s transition and its spin orbit component respectively. The Raman and infra-red spectra of the samples are analyzed to obtain the vibrational modes of the samples. The Kissinger equation is applied to the thermo-grams of differential scanning calorimeter to calculate the activation energy of pure and Fe doped CdSe nanoparticles. The frequency dependent conductivity spectra of the samples are found to follow the power law. © 2013 Published by Elsevier Ltd.

Materials Science in Semiconductor Processing

Phonon modes and activation energy of Fe-doped CdSe nanoparticles

Nanoparticles of cadmium selenide (CdSe) have been synthesized by soft chemical route using mercaptoethanol as a capping agent. X-ray diffraction and transmission electron microscope measurements show that the prepared sample belongs to sphalerite structure with the average particle size of 25 nm. The band gap of the material is found to be 2.1 eV. The photoluminescence (PL) emission spectra of the sample are measured at various excitation wavelengths. The PL spectra appear in the visible region, and the emission feature depends on the wavelength of the excitation. Impedance spectroscopy is applied to investigate the dielectric relaxation of the sample in a temperature range from 323 to 473 K and in a frequency range from 42 Hz to 1.1 MHz. The complex impedance plane plot has been analyzed by an equivalent circuit consisting of two serially connected R-CPE units, each containing a resistance (R) and a constant phase element (CPE). The dielectric relaxation of the sample is investigated in the electric modulus formalism. The temperature dependent relaxation times obey the Arrhenius law. The Havriliak-Negami model is used to investigate the dielectric relaxation mechanism in the sample. The frequency dependent conductivity spectra are found to obey the power law. © 2014 Elsevier Ltd.

Journal	Electronic Materials Letters
Publisher	The Korean Institute of Metals and Materials
ISSN	1738-8090
Open Access	No