YCrO3 Nanoparticles Research Articles

Enhanced electrical and magnetic properties of Sm-doped YCrO3 nanoparticles

Enhanced electrical and magnetic properties of Sm-doped YCrO3 nanoparticles

Structural, electrical and magnetic properties of Eu doped YCrO3 nanoparticles

An enhancement in electrical and magnetic properties was described in chemically prepared YCrO3 nanoparticles by Eu doping. The effect of Eu doping on crystal structure was analyzed by the Rietveld refinement of XRD data. It is observed that the dc conductivity of the samples increases by doping. The temperature variation of dc and ac conductivity of the samples shows that the activation energy decreases after Eu doping. The dielectric study suggests a relaxor like ferroelectric behaviour around 450 K, and with the increase of Eu concentration dielectric constant of the sample increases. The values of retentivity and magnetization increase with the Eu doping confirmed the ferromagnetic ordering in YCrO3 at room temperature which may be due to the decrease of tilting angle. These findings demonstrate the fundamental importance of doping in enhancing the electrical and magnetic properties which will open up the possibility of YCrO3 to be used in spintronic devices.

Effect of neodymium doping on electrical properties and relaxor ferroelectric behavior of YCrO3 nanoparticles

In this research paper we have discussed the electrical, relaxor ferroelectric and ferromagnetic properties of Neodymium (Nd) doped YCrO3 nanomaterial prepared by sol-gel method. The characterization of the samples is followed by X-ray diffraction (XRD) and Transmission electron microscope (TEM). Upon Nd doping the conductivity of the YCrO3 enhances and the samples show semiconducting behavior. It is also found that the dc activation energy is decreased with the increasing doping concentration. Dielectric permittivity supports the modified Cole-Cole model with dc conductivity contribution correction. Both the space charge and free charge carrier dependent conductivity values increase with the increase of doping content. The frequency dependent conductivity study suggests the Dyre's free energy barrier model. Diffused relaxation peak has been observed in different doped samples. The diffuseness factor γ increases with increasing Nd doping concentration. Enhanced relaxer ferroelectric behavior has been noticed with the increasing Neodymium doping content in YCrO3.

Magnetic and dielectric properties of pure and ion doped RCrO3 nanoparticles

Using a microscopic model and the Green’s function technique the magnetic and dielectric properties of YCrO3 and GdCrO3 nanoparticles (NPs) are studied and compared with the bulk properties. Due to different surface exchange interaction constants the magnetization in YCrO3 increases whereas in GdCrO3 decreases with decreasing particle size. The size dependence of the coercive field in GdCrO3 NPs is also discussed. The bulk dielectric constant ϵ′ in YCrO3 is smaller than that in NPs, whereas in GdCrO3 is observed the opposite behavior. The magnetic field influences ϵ′ in YCrO3 NPs which is an indirect evidence for a strong magnetoelectric coupling. The effects of ion doping on ϵ′ are also studied.

The investigation of the electrical transport properties of Gd doped YCrO3 nanoparticles

We report the electrical transport properties of Gd doped YCrO3 nanoparticles synthesized by sol-gel method in the temperature range 298–523K and in the frequency range 100Hz–1MHz. Samples are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Uv–vis absorption spectroscopy. The real and imaginary parts of the dielectric permittivity are followed by Cole-Cole model including electrical conductivity contribution. It is observed that the values for the space charge conductivity and free charge conductivity increase with temperature and the relaxation time decreases with the increase of temperature. The variation of imaginary part of complex electric modulus with frequency at different temperatures shows well defined peaks and considering generalized susceptibility function its asymmetric nature and non – Debye type behavior have been analyzed. The DC and AC activation energy increases with the increase of doping concentration. DC transport properties are analyzed following adiabatic small polaron model.

Effect of La doping on optical and electrical transport properties of nanocrystalline YCrO3

In this work we have reported the synthesis and characterization of La doped YCrO3 nanoparticles following sol-gel method. The optical band gap of the investigated samples decreases with the increase of doping content. Photoluminescence spectra show distinct red light emission in the visible range around 630 nm. Dielectric permittivity is measured within the temperature range 298 K–523 K and in the frequency range 20 Hz – 1 MHz following the power law ε'(f)∝Tp, which shows that the temperature exponent p increases with the decreasing frequency and its values varies from 11.4 to 17 for 1 MHz to 100 KHz frequency variation. The ac impedance analysis shows that grain boundary contribution is dominating over grain contribution. The dc conductivity of the investigated samples follows semiconductor behavior. The analysis of both the dc and ac conductivity shows that the activation energy decreases and the conductivity increases with the increase of doping concentration which is very much important for its application as interconnect material in Solid Oxide Fuel Cells (SOFCs).

Citrate precursor synthesis and multifunctional properties of YCrO3 nanoparticles

Monophasic and multifunctional YCrO3 nanoparticles (22 nm) with a high surface area of 344 m2 g−1 exhibit well-defined multiferroic characteristics.

Investigation of dielectric and electrical behavior of Mn doped YCrO3 nanoparticles synthesized by the sol gel method

In the present work Mn doped YCrO3 nanoparticles are synthesized by the sol–gel method. Samples have been characterized by the X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis absorption spectroscopy. The optical band gap of Mn doped YCrO3 nanoparticles increases with increase of doping concentration. The dc resistivity of the prepared samples decreases with increasing temperature. The variation of ac conductivity with frequency has been explained by the Correlated Barrier Hoping (CBH) conduction mechanism. Dielectric permittivity of the samples was studied and it follows the power law ε/(f)∝Tn, where the temperature exponent n is found to be frequency dependent. The dielectric properties of the samples have been discussed in terms of electric modulus vector. Both activation energies due to dc resistance and dielectric response have been measured for the different samples and it is observed that it increases with the Mn content.

Synthesis of YCrO3 nanoparticles through PAA assisted sol–gel route

We report the synthesis of nanocrystalline phase-pure YCrO3 powders by a poly acrylic acid (PAA) assisted sol–gel process at a comparatively low calcination temperature of 600 °C. The role of PAA in the powder processing was investigated systemically using Fourier transform infrared (FTIR) spectroscopy, differential thermal and thermogravimetric analyzer (DT/TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). PAA is found to have the desirable property of forming stable complexes with the cations, Y3+ and Cr3+ at a low pH. FTIR results demonstrated that in the gel-precursor, the carboxylate groups of PAA bond to Y3+ and Cr3+ in a monodentate and a bridging bidentate configuration, respectively, owing to the properties of Cr3+ giving the best correlation with PAA. The obtained particles have capsule-like morphology with a mean diameter of 40 nm. It is presumed that this morphology is due to the extended-chain configuration of PAA in the aqueous solution. The method showed a good control over particle size, morphology, chemical homogeneity, stoichiometry and agglomeration of the powders.

Two-photon assisted excited state absorption in multiferroic YCrO3 nanoparticles

We report a novel functionality for the ferroelectric-antiferromagnet YCrO3 powder of optical limiting upon illumination by nanosecond laser pulses at 532nm. The optical limiting properties are investigated using the open aperture z-scan technique. The obtained nonlinearity fits to a three-photon like absorption mechanism. It is proposed that this nonlinearity is caused by two-photon absorption, followed by excited state absorption. Two different sized samples were investigated and the nonlinearity is found to be size dependent.