Structural and optical characterization of Cr2O3 nanostructures: Evaluation of its dielectric properties

Abstract

Articles you may be interested inThe Cr-substitution concentration dependence of the structural, electric and magnetic behaviors for Aurivillius Bi5Ti3FeO15 multiferroic ceramics J. Appl. Phys. 114, 234101 (2013); 10.1063/1.4849055Conversion of CH4/CO2 to syngas over Ni-Co/Al2O3-ZrO2 nanocatalyst synthesized via plasma assisted coimpregnation method: Surface properties and catalytic performance Synthesis of TiO 2 nanoparticles by hydrolysis and peptization of titanium isopropoxide solution AIP Conf.The structural, optical and dielectric properties of as-grown Cr 2 O 3 nanostructures are demonstrated in this paper. Powder X-ray diffractometry analysis confirmed the rhombohedral structure of the material with lattice parameter, a = b = 4.953 Å; c = 13.578 Å, and average crystallize size (62.40 ± 21.3) nm. FE-SEM image illustrated the mixture of different shapes (disk, particle and rod) of as-grown nanostructures whereas; EDS spectrum confirmed the elemental purity of the material. FTIR spectroscopy, revealed the characteristic peaks of Cr-O bond stretching vibrations. Energy band gap (3.2 eV) of the nanostructures has been determined using the results of UV-VIS-NIR spectrophotometer. The dielectric properties of the material were checked in the wide frequency region (100Hz-30 MHz). In the low frequency region, the matrix of the dielectric behaves like source as well as sink of electrical energy within the relaxation time. Low value of dielectric loss exhibits that the materials posses good optical quality with lesser defects. The ac conductivity of the material in the high frequency region was found according to frequency power law. The physical-mechanism and the theoretical-interpretation of dielectric-properties of Cr 2 O 3 nanostructures attest the potential candidature of the material as an efficient dielectric medium. C 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

Doping of Ga in antiferromagnetic semiconductor α-Cr2O3 and its effects on magnetic and electronic properties

“…The peak at about 365 nm is associated with the conventional band gap ( 3 eV) of α-Cr 2 O 3 [13]. The absorption peaks at around 460 nm and 600 nm correspond to 4 A 2g → 4 T 1g and 4 A 2g → 4 T 2g 3d 3 electronic transitions of octahedral Cr 3+ ions [22].…”

“…It is difficult to classify whether the peaks are due to direct or indirect electronic transitions for wide band gap semiconductors, like α-Cr 2 O 3 . In such case, Tauc relation: ℎ = (ℎ − ) [13] has been used to calculate the band gap (E g ). The exponent n = 1/2 and 2 are applicable for direct and indirect electronic transitions, respectively.…”

“…Among the traditional AFM oxides, α-Cr 2 O 3 is a green colored compound that stabilizes in corundum (rhombohedral) structure with optical band gap  3 eV [13] and used in the field of visible light driven photo catalysis, hydrogen storage, photonic and electronic devices and drug delivery [13][14][15]. Recently, some efforts have been made to develop magnetic semiconductors by doping magnetic Cr atoms into the lattices of wide band gap semiconductors (Al 2 O 3 , Ga 2 O 3 , ZnO) which can provide suitable materials for applications in spintronics and optoelectronics devices.…”

Two‐Dimensional Amorphous Cr2O3 Modified Metallic Electrodes for Hydrogen Evolution Reaction

“…To study the type of bonding present in the 2D Cr 2 O 3 sheets, Fourier‐transform infrared (FTIR) spectrum was recorded (Figure d) and compared with the commercially available pristine Cr 2 O 3 . In most of the cases, the metal oxide symbolizes the peaks below 1000 cm −1 resulting out of inter‐atomic vibrations . The obtained modes are summarized in Table S1, Supporting Inforamtion.…”

Structural Characterization of NiO/Cr2O3Composites and Hydrothermal Synthesis, Properties Gas Sensing

“…Its applications are extended by changing its physical and chemical properties under nanoscale due to large range of surface to volume ratio [3]. In spite of unusual structural geometry, semiconductor metal oxide nanostructures are of great interest of research in nanoscience and nanotechnology, because of the fact that this class of compound is frequently revealing the novel properties relative to their coarsegrained counterparts, due to their reduced size and large surface area [4]. The chosen metal oxide nanoparticles like chromic oxide and nickel oxide is an important transition metal oxide of p-type semiconducting materials with a band gap of 3 eV and 3.8 eV.…”