STRUCTURE, ELECTRICAL TRANSPORT AND MAGNETO-RESISTANCE PROPERTIES OFLa5/8Ca3/8MnO3MANGANITE SYNTHESIZED WITH DIFFERENT MANGANESE PRECURSORS

2012 ◽  
Vol 26 (06) ◽  
pp. 1150039 ◽  
Author(s):  
M. NAVASERY ◽  
S. A. HALIM ◽  
K. P. LIM ◽  
S. K. CHEN ◽  
A. S. ROSLAN ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Single Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Route Selection ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Magneto Resistance

We synthesized the polycrystalline manganite of La5/8Ca3/8MnO3with three different manganese routes prepared through a solid state reaction method. The effects of the manganese route selection on the structure, electrical transport and magneto-transport properties were examined in this study. The samples were characterized using X-ray diffraction (XRD) and SEM to identify their structure and morphology. XRD analysis confirmed that all samples were in single phase with orthorhombic structure and belonged to the Pnma space group. The average grain sized samples with manganese route of Mn2O3and MnCO3had a grain size of 1.2–8.7 μm and 2–7.5 μm, respectively. For the MnO2route, the sample had a small melt-like shape with higher porosity. The metal–insulator transition temperature, TMI, for LCMO ( Mn2O3), LCMO ( MnO2) and LCMO ( MnCO3) samples were 270 K, 266 K and 258 K, respectively. All the samples showed negative magneto-resistance with significant increase in value near the TMItemperature. The highest CMR (colossal magneto-resistance) ratio was found in LCMO ( Mn2O3), -22.06% at 270 K, followed by -16.69% for LCMO ( MnO2) at 80 K, and 15.2% for LCMO ( MnCO3) at 100 K in a 1 T magnetic field.

STUDY OF STRUCTURAL, ELECTRICAL TRANSPORT AND MAGNETIC PROPERTIES IN La1-xAgxMnO3 COMPOUNDS

2004 ◽  
Vol 18 (05n06) ◽  
pp. 221-231 ◽  
Author(s):  
MANORANJAN KAR ◽  
S. RAVI
Keyword(s):  
Magnetic Field ◽  
Electrical Transport ◽  
Single Phase ◽  
Ac Susceptibility ◽  
X Ray Diffraction ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Phase Form ◽  
X Ray ◽  
Maximum Value

X-ray diffraction, electrical resistivity and ac susceptibility measurements have been carried out on La 1-x Ag x MnO 3 compounds for x=0.05 to 0.30. These samples are found to be in single phase form with [Formula: see text] space group and with typical lattice parameters a=b=5.524Å and c=13.349Å for x=0.05 sample. The Mn–O–Mn bond angles and variance, σ2 are found to increase with doping. Metal-insulator transitions in the temperature range 254 to 259 K have been observed. These materials exhibit paramagnetic to ferromagnetic transitions in the vicinity of metal-insulator transition temperatures. The paramagnetic susceptibility could be analyzed using Curie–Weiss law. All the above samples exhibit colossal magneto-resistivity and its maximum value is found to be 73% for x=0.15 sample at 50 kOe magnetic field.

Structural, Magnetic, and Transport Properties of La0.62Sb0.38MnO3 Ceramic

2013 ◽  
Vol 800 ◽  
pp. 398-401 ◽  
Author(s):  
Qiang Wang ◽  
Ping Duan ◽  
Ji You Wang ◽  
Lei Chang ◽  
Jin Liang Zhao ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
State Transition ◽  
Ferromagnetic State ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Electrical Transport Properties ◽  
Metal Insulator ◽  
X Ray

The polycrystalline La0.62Sb0.38MnO3 sample has been prepared by the solid-state reaction method. Structural, magnetic and electrical transport properties have been researched. X-ray diffraction analysis confirms the hexagonal crystal symmetry. Magnetization measurements indicate La0.62Sb0.38MnO3 experienced from paramagnetic to ferromagnetic state transition with decreasing temperature at about 225 K. Resistivity dependences on temperature exhibit metal-insulator transition (MIT), and the maximum magnetoresistance (MR) ratio is about 33 % at temperature of 189 K and magnetic field of 2 T.

Synthesis of Polycrystalline LaYO3 with Different Sintering Temperature

2015 ◽  
Vol 819 ◽  
pp. 117-122 ◽  
Author(s):  
N.A. Shafiqa ◽  
M.S. Idris ◽  
C.A. Salmie Suhana ◽  
R.A.M. Osman ◽  
T.Q. Tan
Keyword(s):  
Single Phase ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Pure Phase ◽  
Perovskite Ceramic

Synthesis of LaYO3 was carried out via conventional solid state reaction method. The polycrystalline samples were sintered at temperatures in the range of 1300 °C to 1500 °C with each deviation is 50 °C. X-ray diffraction (XRD) analysis indicated that the perovskite ceramic obtained its single phase at 1500 °C with ordered monoclinic perovskite structure. The pure phase sample showed 98.79 % relative density and scanning electron micrographs also proved that the porosity of the sample reduced when sample undergo sintering.

PREPARATION AND CHARACTERIZATION OF SOME COLOSSAL MAGNETO-RESISTANCE MATERIALS

2002 ◽  
Vol 16 (15n16) ◽  
pp. 589-594
Author(s):  
V. RAJAKUMARI ◽  
K. PADMAVATHI ◽  
M. VITTAL ◽  
V. PRASAD ◽  
S. V. SUBRAHMANYAM ◽  
...  
Keyword(s):  
Single Phase ◽  
Diffraction Method ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Magneto Resistance ◽  
Better Than

A series of GMR materials with compositional formula Re 0.67 Sr 0.33 MnO 3, where Re = La, Nd, Sm, Gd, Pr, etc. and their combinations were prepared by the solid state reaction method. All the samples were characterized by the powder X-ray diffraction method and the patterns show that the samples are single phase with orthorhombic structure. Resistivity measurements were also carried out by the four probe method in the temperature range 80–300 K and from these results, Metal–Insulator (M–I) transition temperatures of the samples were obtained. Finally, the magneto-resistance measurements were also carried out as a function of magnetic field and temperature over a temperature range 80–300 K. It has been observed that the magneto-resistance of Lanthanum-based mixed compositions is better than that of pure compositions.

scholarly journals Structural, Dielectric and Magnetic Properties of Al3+ and Cr3+ Substituted Ni-Zn-Cu Ferrites

2018 ◽  
Vol 4 (5) ◽  
pp. 487-491 ◽  
Author(s):  
G. Satyanarayana ◽  
G. Nageswara Rao ◽  
K. Vijaya Babu
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Single Phase ◽  
Fourier Transforms ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Pulse Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Loop Technique

Ferrite materials with the general formula Ni0.7Zn0.2Cu0.1Fe1.9M0.1O4 (M=Al and Cr) are synthesized by using the solid state reaction method. X-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectra, scanning electron microscope (SEM) dielectric measurements and vibrating sample magnetometer (VSM) techniques are utilized to study the various properties of the synthesized ferrites. XRD analysis confirmed the formation of single phase cubic spinel structure and the crystallite size is calculated by Scherrer’s formula found to be 20.3 and 12.5 nm. The magnetic properties were studied using pulse field hysteresis loop technique at room temperature. The saturation magnetization exhibit 98.71 and 91.69 emu/g for Al3+ and Cr3+ substituted Ni-Zn-Cu ferrites respectively. The magnetic permeability is increasing for chromium substituted compound in the frequency range 100 Hz to 120 MHz and significant modification in DC conductivity is explained on the basis of hopping mechanism.

Synthesis and Dielectric Properties of Ba(Ti,Y)O3 Solid Solutions to Ba3Ti2YO8.5-BaTiO3 Composites

2011 ◽  
Vol 194-196 ◽  
pp. 109-112
Author(s):  
Min Huang ◽  
Yun Wu Wang
Keyword(s):  
Single Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Microstructure Observation ◽  
Ceramic Samples ◽  
Scanning Electron

Ceramic samples with the nominal composition (1-x) BaTiO3 + x Ba3Ti2YO8.5 (x = 0 - 0.4) were prepared by the solid-state reaction method. The X-ray diffraction (XRD) analysis and the lattice parameters determination indicate that the samples with x≤ 0.16 exhibit a single phase cubic perovskite structure. When x > 0.16, the system is of biphasic composites, which consist of Ba(Ti0.911Y0.089)O3 and Ba3Ti2YO8.5. The microstructure observation by Scanning Electron Microscopy (SEM) supports the XRD result. For the biphasic composites, the dielectric constant follows the Lichtenecker relation in a wide temperature range.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

Structural, Dielectric and Electrical Studies of Ba4CaRTi3Nb7O30 (R = Eu, Dy) Ferroelectric System

2013 ◽  
Vol 547 ◽  
pp. 41-48 ◽  
Author(s):  
Prasun Ganguly ◽  
A.M. Biradar ◽  
A.K. Jha
Keyword(s):  
Single Phase ◽  
Microstructural Analysis ◽  
Tungsten Bronze ◽  
Negative Temperature ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Paraelectric Phase Transition ◽  
Orthorhombic Crystal Structure

The polycrystalline samples of Ba4CaRTi3Nb7O30 (R = Eu, Dy), members of tungsten-bronze family, were prepared by high-temperature solid state reaction method and studied for their dielectric and electrical properties. X-ray diffraction (XRD) analysis reveals the formation of single-phase compounds having orthorhombic crystal structure at room temperature. Microstructural analysis by scanning electron microscope (SEM) shows that the compounds have well defined grains, which are distributed uniformly throughout the sample. Detailed dielectric properties of the compounds as a function of frequency and temperature show that the compounds undergo non-relaxor kind of ferroelectric-paraelectric phase transition of diffuse nature. Ferroelectric, piezoelectric and pyroelectric studies of the compounds have been discussed in this paper. The temperature dependence of dc conductivity of the compounds have been investigated. The conductivity study over a wide temperature range suggests that the compounds have negative temperature coefficient of resistance (NTCR) behaviour.

PREPARATION OF SOME NANO SIZE COLOSSAL MAGNETO RESISTANCE MATERIALS BY THE SOL-GEL ROUTE

2003 ◽  
Vol 17 (01) ◽  
pp. 19-24 ◽  
Author(s):  
K. PADMAVATHI ◽  
V. RAJAKUMARI ◽  
M. VITHAL ◽  
V. PRASD ◽  
S. V. SUBRAMANYAM ◽  
...  
Keyword(s):  
Single Phase ◽  
Sol Gel ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Resistivity Measurements ◽  
Temperature Range ◽  
Ionic Size ◽  
Colossal Magneto Resistance ◽  
Magneto Resistance ◽  
Nano Size

A series of colossal magneto resistance materials having compositional formula Re 0.67 Sr 0.33 MnO 3 (Re = Nd, Gd, … etc.) were prepared by the sol-gel method, using Ethylene glycol as a gelating reagent. The materials were characterized by the powder X-ray diffraction technique and are found to be single phase with orthorhombic structure. The particle size of all the materials were calculated using the well known Shearer formula and are found to be in the range of 20–45 nm. In order to determine the transition temperature (T c ), the DC electrical resistivity measurements were also carried out over a temperature range 80–300 K using the four probe method and it has been observed that the T c values are found to increase with increasing ionic size. Finally the magneto resistance measurements were also undertaken in the temperature range 80–300 K and it has been found that the MR values of these materials are better when compared with those prepared by the solid state reaction method.

Colossal Magnetoresistance in Thick La0.7Ca0.3MnO3 Films

1995 ◽  
Vol 384 ◽  
Author(s):  
Randolph E. Treece ◽  
P. Dorsey ◽  
M. Rubinstein ◽  
J. M. Byers ◽  
J. S. Horwitz ◽  
...  
Keyword(s):  
Colossal Magnetoresistance ◽  
Single Phase ◽  
Laser Deposition ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Mr Effect ◽  
Deposited Films ◽  
Post Deposition

ABSTRACTThick films (0.6 and 2.0 μm) of the colossal magnetoresistance (CMR) material, La0.7Ca0.3MnO3 (LCMO), have been grown by pulsed laser deposition (PLD). The films were grown from single-phase LCMO targets in 100 mTorr 02 pressures and the material deposited on (100) LaAlO3 substrates at deposition temperatures of 800°C. The deposited films were characterized by X-ray diffraction (XRD), magnetic field-dependent resistivity, and Rutherford backscattering spectroscopy (RBS). The LCMO films were shown by XRD to adopt an orthorhombic structure. Brief post-deposition annealing led to ~50,000% and ~12,000% MR effect in the 0.6 μm and 2.0 μm films, respectively.

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