scholarly journals Doping Effect on Piezoelectric, Magnetic and Magnetoelectric Properties of Perovskite—Ferromagnetic Magnetoelectric Composites

2021 ◽  
Author(s):  
Rashed A. Islam
Keyword(s):  
Curie Temperature ◽  
Misfit Strain ◽  
Lattice Parameter ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetoelectric Properties ◽  
Magnetoelectric Coefficient ◽  
Almost All ◽  
Magnetostrictive Composites

This chapter explains the effect of compositional modification on the magnetoelectric coefficient in sintered piezoelectric – magnetostrictive composites. It was found that 15 at% doping of Pb(Zn1/3Nb2/3)O3 [PZN] in Pb(Zr0.52Ti0.48)O3 [PZT] enhances the piezoelectric and magnetoelectric properties of a PZT – 20 at% Ni0.8Zn0.2Fe2O4 [NZF] composite. The effect of doping on the ferromagnetic phase was also investigated. With increases in Zn concentration, it was found that the coercive field and Curie temperature of Ni(1-x)ZnxFe2O4 [NZF] decreases, while its saturation magnetization has a maxima at 30 mole% Zn. X-ray diffraction revealed that the lattice constant of NZF increases from 8.32 Å for 0 at% Zn to 8.39 Å for 50 at% Zn. The magnetoelectric coefficient was found to have a maxima of 144 mV/cm.Oe at 30 at% Zn. To understand better, the effect of 40% (by mole) Zn substitution on structural, piezoelectric, ferromagnetic and magnetoelectric properties of Pb(Zr0.52Ti0.48)O3 - CoFe2O4 (PZT - CFO) sintered composite is also explained. X-ray diffraction of Co0.6Zn0.4Fe2O4 (CZF) showed the shift in almost all diffraction peaks to lower diffraction angle confirming the increase in lattice parameter in all three direction from 8.378 (for CFO) to 8.395 Å for (Co,Zn)Fe2O4 (CZF). SEM and TEM results showed defect structure (cleavage, twins, strain fields) in the CZF particle, which is a clear indication of misfit strain developed due to lattice expansion. Magnetic properties measured over temperature (5 K – 1000 K) showed increased magnetization but lower magnetic Curie temperature in PZT - CZF particle. Magnetoelectric coefficient measured as function of ferrite concentration showed an increase of more than 100% after doping the CFO phase with 40% Zn. This enhancement can be attributed to increase in the lattice strain, magnetic permeability and decrease in coercivity.

scholarly journals Effects Of Cd On Physical And Some Magnetic Properties Of Co-Cd Ferrites

1970 ◽  
Vol 35 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Saroaut Noor ◽  
SS Sikder ◽  
M Samir Ullah ◽  
MA Hakim ◽  
Shireen Akhter
Keyword(s):  
Curie Temperature ◽  
Lattice Parameter ◽  
Initial Permeability ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Cobalt Ferrites ◽  
Vegard’S Law ◽  
Ray Density ◽  
Curie Temperature Tc

Polycrystalline samples of Cd substituted cobalt ferrites with composition Co1-xCdxFe2O4 (x = 0.0- 0.6 in steps of 0.1) were prepared by double sintering ceramic method. The samples were sintered at 1050°C for 3 hours. X-ray diffraction pattern of the samples showed single phase cubic spinel structure. It was found that the lattice parameter increases linearly with increasing Cd content following Vegard’s law. The apparent density and X-ray density exhibited similar behavior. The Curie temperature Tc has been determined from the temperature dependence of permeability. It was found that the Curie temperature continuously decreased with increasing Cd content and is attributed to the weakening of JAB exchange interaction. The initial permeability, μ' increases with increasing Cd content up to x = 0.6 and then decreases. Key words: Co-Cd ferrite; Lattice parameter; Permeability DOI: http://dx.doi.org/10.3329/jbas.v35i2.9429 JBAS 2011; 35(2): 229-235

Synthesis of Ferromagnetic Germanides in 40Ge/60Mn Films: Magnetic and Structural Properties

2014 ◽  
Vol 215 ◽  
pp. 167-172
Author(s):  
Victor G. Myagkov ◽  
A.A. Matsunin ◽  
Y.L. Mikhlin ◽  
Victor S. Zhigalov ◽  
Liudmila E. Bykova ◽  
...  
Keyword(s):  
Solid State ◽  
Curie Temperature ◽  
Photoelectron Spectroscopy ◽  
Magnetic Measurements ◽  
Atomic Ratio ◽  
Photoelectron Spectra ◽  
Solid State Reactions ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray

Solid-state reactions between Ge and Mn films are systematically examined using X-ray diffraction, photoelectron spectroscopy and magnetic measurements. The films have a nominal atomic ratio Ge:Mn = 40:60 and are investigated at temperatures from 50 to 500 °С. It is established that after annealing at ~120 °С, the ferromagnetic Mn5Ge3 phase is the first phase to form at the 40Ge/60Mn interface. Increasing the annealing temperature to 500 °С leads to the formation of the ferromagnetic phase with a Curie temperature TC ~ 360 K and magnetization MS ~ 140-200 emu/cc at room temperature. Analysis of X-ray diffraction patterns and the photoelectron spectra suggests that the increased Curie temperature and magnetization are related to the migration of C and O atoms into the Mn5Ge3 lattice and the formation of the Nowotny phase Mn5Ge3СxOy. The initiation temperature (~120 °С) of the Mn5Ge3 phase is the same both for solid-state reactions in Ge/Mn films, as well as for phase separation in GexMn1-x diluted semiconductors. We conclude that the synthesis of the Mn5Ge3 phase is the moving force for the spinodal decomposition of the GexMn1-x diluted semiconductors.

Effect of Temperature of Synthesis on X-Ray, Infrared Spectroscopic Study and Magnetic Properties of Magnesium Zinc Ferrites

2013 ◽  
Vol 547 ◽  
pp. 57-69 ◽  
Author(s):  
Sujata. S. Khot ◽  
Neelam S. Shinde ◽  
Bhimrao P. Ladgaonkar ◽  
Bharat B. Kale ◽  
Shrikant C. Watawe
Keyword(s):  
Curie Temperature ◽  
Saturation Magnetization ◽  
Ac Susceptibility ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
Ir Absorption ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray

Some physical properties (such as lattice parameter, curie temperature, ac susceptibility) of Mg1-xZnxFe2O4 (where x = 0.3,0.4,0.5,0.6) ferrites have been studied. Magnesium Zinc Ferrites was synthesized by oxalate co-precipitation method at different synthesis temperature and characterized by X-ray diffraction and far IR absorption techniques, scanning Electron microscopy .The lattice parameter were computed. The X-ray diffraction studies reveal the formations of single phase cubic spinel structure.IR absorption bands are observed around 600 cm-1 and 400 cm-1 on the tetrahedral and octahedral sites respectively. Magnetization parameters such as saturation magnetization, and magnetic moment were calculated and the results are discussed with the help of the existing theories. Saturation magnetization was found to be in the range 2 emu/gm to 8.28 emu/gm when the samples were synthesized below 100°C. The variation of A.C. susceptibility with temperature shows the existence of super paramagnetic nature. The Curie temperature was determined from the measurement of the susceptibility verses temperature. The SEM micrograph shows the uniform distribution of the particles, the average size was estimated to be 0. 350 µm.

Structure and Magnetocaloric Effect of B-Doped Mn-Fe-P-Si Compounds

2021 ◽  
Vol 323 ◽  
pp. 152-158
Author(s):  
Shou Yuan Xing ◽  
Song Lin ◽  
Zhi Qiang Song ◽  
Zhi Qiang Ou
Keyword(s):  
Crystal Structure ◽  
Curie Temperature ◽  
Lattice Parameter ◽  
Magnetic Entropy ◽  
Field Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
P Type ◽  
Type Crystal

We reported the structural, magnetic and magenetocaloric properties of Mn1.25Fe0.75P0. 50Si0.50Bx(x = 0.01, 0.02 and 0.04) X-ray diffraction patterns show that all compounds crystallize in the hexagonal Fe2P-type crystal structure. Lattice parameter a increases while c decreases with increasing B contents. The Curie temperature of the compounds have been determined, the values are 219, 268 and 323.2 K for x = 0.01, 0.02, 0.04, respectively. The maximum magnetic entropy changes in a field change of 0~1.5 T are 6.1, 5.3 and 3.5J/kg·K for x = 0.01, 0.02 and 0.04, respectively.

scholarly journals Characterization And Curie Temperature Of Co Doped Ni-Zn Perminvar Ferrite

1970 ◽  
Vol 35 (2) ◽  
pp. 171-178 ◽  
Author(s):  
MD Sohal Rana ◽  
Rabindra Chandra Sinha ◽  
DK Saha
Keyword(s):  
Curie Temperature ◽  
Quality Factor ◽  
Lattice Parameter ◽  
Initial Permeability ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Zn Content ◽  
Diffraction Lattice ◽  
Relative Quality

Ni-Zn perminvar ferrites having the compositions Co0.02Zn0.20Ni0.58Fe2.2O4 and Co0.02Zn0.28 Ni0.50Fe2.2O4 were prepared through the solid state reaction using conventional ceramic method. The homogeneous phase of perminvar ferrites has been observed from the study of X-ray diffraction. Lattice parameter of the samples was found to be 8.369, 8.372 and 8.375Å for the sample Co0.02Zn0.20Ni0.58Fe2.2O4 and 8.382, 8.383 and 8.384Å for the sample Co0.02Zn0.28 Ni0.50Fe2.2O4 sintered at 1200, 1300 and 1350°C respectively. Both the bulk density and porosity decreases with Zn content and sintering temperatures. The values of Curie temperature of the two compositions were found to be 511, 508 and 508°C (for TS = 1200, 1300 and 1350°C) for the sample of Co0.02Zn0.20Ni0.58Fe2.2O4 and 460 and 455°C (for Ts = 1300 and 1350°C) for the sample of Co0.02Zn0.28Ni0.50Fe2.2O4, respectively. Frequency dependence permeability spectra, revealed that permeability of all the samples is almost independent of frequency up to 1 MHz. It is observed that permeability increases with Zn content and hence the relative quality factor decreases with increasing Zn content. Key words: Perminvar ferrite; Curie temperature; Initial permeability; Quality factor DOI: http://dx.doi.org/10.3329/jbas.v35i2.9421 JBAS 2011; 35(2): 171-178

scholarly journals Structural and Electrical Properties of Li–Ni Nanoferrites Synthesised by Citrate Gel Autocombustion Method

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
G. Aravind ◽  
D. Ravinder ◽  
V. Nathanial
Keyword(s):  
Curie Temperature ◽  
Structural Parameters ◽  
Lattice Parameter ◽  
Measured Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Ferrites ◽  
Structural And Electrical Properties ◽  
Ray Density ◽  
Lcr Meter

An attempt has been made to synthesize nanocrystalline lithium-nickel ferrites with a compositional formula Li0.5−0.5xNixFe2.5−0.5xO4 (where x=0.0 to 1.0 with step of 0.2) by a low temperature citrate gel autocombustion method. Single phase cubic structure is confirmed by X-ray diffraction analysis. This result demonstrates that the prepared samples are homogeneous and the sharp peaks reveal that the samples are in good crystalline form. As the Ni concentration is increased, various interesting changes in the values of the structural parameters like lattice parameter, X-ray density, bulk density, and porosity have been observed. The surface morphology of the prepared samples was studied using scanning electron microscopy (SEM). The DC resistivity measurements were carried out using two-probe method from 200°C to 600°C. The variation of log⁡(σT) with reciprocal of temperature shows a discontinuity at Curie temperature. log⁡(σT) versus 1/T plot of the pure lithium ferrites is almost linear which indicates the Curie temperature of the pure lithium ferrites was beyond our measured temperature. The dielectric properties of these ferrites have been studied using a LCR meter from the room temperature to 700 K at various frequencies up to 5 MHz, which reveals that all the prepared samples have dielectric transition temperature around 600 K.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

scholarly journals Measurements by x-ray diffraction of the temperature dependence of lattice parameter and crystallite size for isostatically-pressed graphite

Carbon Trends ◽  
2021 ◽  
pp. 100071
Author(s):  
Keith R. Hallam ◽  
James Edward Darnbrough ◽  
Charilaos Paraskevoulakos ◽  
Peter J. Heard ◽  
T. James Marrow ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Crystallite Size ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray

Problems Associated with Kα Doublet in Residual Stress Measurements

1979 ◽  
Vol 23 ◽  
pp. 333-339
Author(s):  
S. K. Gupta ◽  
B. D. Cullity
Keyword(s):  
Residual Stress ◽  
Silicon Powder ◽  
Lattice Parameter ◽  
Diffraction Peak ◽  
Parameter Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
The Difference ◽  
Similar Accuracy

Since the measurement of residual stress by X-ray diffraction techniques is dependent on the difference in angle of a diffraction peak maximum when the sample is examined consecutively with its surface at two different angles to the diffracting planes, it is important that these diffraction angles be obtained precisely, preferably with an accuracy of ± 0.01 deg. 2θ. Similar accuracy is desired in precise lattice parameter determination. In such measurements, it is imperative that the diffractometer be well-aligned. It is in the context of diffractometer alignment with the aid of a silicon powder standard free of residual stress that the diffraction peak analysis techniques described here have been developed, preparatory to residual stress determinations.

scholarly journals MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics

2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  
Keyword(s):  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Optoelectronic Devices ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Energy ◽  
Movpe Growth ◽  
Pl Emission

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.

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