Structural changes, magnetic properties and dielectric behaviour of Tb3+ doped Ni-Cd mixed ferrites

2019 ◽  
Author(s):  
Binu P. Jacob ◽  
P. Laneesh
Keyword(s):  
Magnetic Properties ◽  
Structural Changes ◽  
Dielectric Behaviour ◽  
Mixed Ferrites

EXAFS Study of Co/Ag Multilayers

1993 ◽  
Vol 307 ◽  
Author(s):  
C. L. Foiles ◽  
R. Loloee ◽  
T. I. Morrison
Keyword(s):  
Magnetic Properties ◽  
Significant Role ◽  
Giant Magnetoresistance ◽  
Structural Changes ◽  
Multilayer System ◽  
Basic Form ◽  
Exafs Data ◽  
Simple Scaling ◽  
Exafs Study

ABSTRACTCo EXAFS data for these Co/Ag multilayers exhibit no changes in basic form and obey a simple scaling with Co thickness down to 6Å. Over this same thickness range the giant magnetoresistance and the manner in which magnetization approaches saturation change substantially. These results indicate that local structural changes do not play a significant role in altering the magnetic properties of this multilayer system.

The Production and Properties of Copper-Iron Particulate Composite Wire

1989 ◽  
Vol 203 (3) ◽  
pp. 175-184
Author(s):  
G I Lawal ◽  
D C Barton ◽  
A N Bramley ◽  
J Nutting
Keyword(s):  
Magnetic Properties ◽  
Structural Changes ◽  
Copper Wire ◽  
Particulate Composite ◽  
Iron Particle ◽  
Composite Wire ◽  
Particulate Form ◽  
Increasing Process ◽  
The Wire ◽  
Magnetic Hardness

A novel means of producing copper-based powder metallurgy wire containing sufficient iron in particulate form to impart useful magnetic properties has been investigated. The method, which involves encapsulating a powder mixture within a copper tube prior to rolling and die-drawing operations, has been successfully used to produce composite wire of diameter range 1.8-0.4 mm. Particular attention has been paid to the effect of composition, processing strain, heat treatment and iron particle size on the electrical, mechanical and magnetic properties of the wire. Microscopy studies have also been carried out to determine structural changes in the material during processing. It was found that the good conductivity and ductility of solid copper wire was not greatly reduced provided (a) the iron content of the composite wire was kept fairly low (<6 per cent) and (b) the annealing temperature was not sufficiently high for significant alloying to take place (650°C maximum). Saturation magnetization values increased with increasing process strain, as did the magnetic hardness. The latter, however, could be minimized by fully annealing the iron after processing the wire. The magnetic properties were undoubtedly influenced by the size and shape of the iron particles, smaller particles being more easily elongated and tending to give greater magnetic hardness.

scholarly journals Co-doped MnFe2O4 nanoparticles: magnetic anisotropy and interparticle interactions

2019 ◽  
Vol 10 ◽  
pp. 856-865 ◽  
Author(s):  
Bagher Aslibeiki ◽  
Parviz Kameli ◽  
Hadi Salamati ◽  
Giorgio Concas ◽  
Maria Salvador Fernandez ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Structural Changes ◽  
Spherical Shape ◽  
Average Diameter ◽  
Cobalt Doping ◽  
Interparticle Interactions ◽  
Co Doping ◽  
Particle Anisotropy ◽  
Interaction Regime

The effect of cobalt doping on the magnetic properties of Mn1− x Co x Fe2O4 nanoparticles was investigated. All samples consist of ensembles of nanoparticles with a spherical shape and average diameter of about 10 nm, showing small structural changes due to the substitution. Besides having the same morpho-structural properties, the effect of the chemical composition, i.e., the amount of Co doping, produces marked differences on the magnetic properties, especially on the magnetic anisotropy, with evident large changes in the coercive field. Moreover, Co substitution has a profound effect on the interparticle interactions, too. A dipolar-based interaction regime is detected for all samples; in addition, the intensity of the interactions shows a possible relation with the single particle anisotropy. Finally, the sample with the strongest interaction regime shows a superspin glass state confirmed by memory effect dynamics.

Dielectric Behaviour of Ice Microcrystals: A Study Versus Temperature

1979 ◽  
Vol 22 (86) ◽  
pp. 145-154 ◽  
Author(s):  
Christian Boned ◽  
Bernard Lagourette ◽  
Marc Clausse
Keyword(s):  
Melting Point ◽  
Aqueous Solutions ◽  
Structural Changes ◽  
The Other ◽  
Dielectric Behaviour ◽  
Dielectric Relaxations ◽  
General Radio ◽  
Lower Temperature Range ◽  
Lower Temperature ◽  
Oil Type

AbstractDispersions of ice microcrystals were obtained from the breakdown of supercooling of water-in-oil type emulsions whose disperse phase was either resin-exchanged water or aqueous solutions of NH4Cl. Their complex permittivity ε⋆ = ε´–jε˝ was studied versus temperatureT,up to the melting point of ice microcrystals, by means of an automatically balancing admittance bridge (General Radio 1680 A) working at 400 Hz and 1 kHz, The plots ε´(T), ε˝(T) and ε˝(ε´) reveal that these systems exhibit two distinct dielectric relaxations located on either side of a temperatureTmwhich was found to be equal to about — 20°C in the case of water and lower than — 20°C in the case of aqueous solutions of NH4Cl. The relaxation located in the lower temperature range arises from the Debye dipolar absorption of ice while the other one could be related to structural changes occurring within the lattice of ice asTapproaches its melting point. These results are consistent with those obtained by investigating versus frequency the dielectric behaviour of ice monocrystals at discrete sub-zero temperatures close to their melting point.

Structural changes and physical properties of Fe–Ni-based metallic glasses rapidly heated by pulsed electrical currents

1991 ◽  
Vol 6 (5) ◽  
pp. 1028-1034 ◽  
Author(s):  
L. Zaluski ◽  
A. Zaluska ◽  
M. Kopcewicz ◽  
R. Schulz
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Metallic Glasses ◽  
Structural Changes ◽  
Annealing Treatment ◽  
Electrical Current ◽  
Liquid Nitrogen Temperature ◽  
Alpha Phase ◽  
Thermal Spike ◽  
Electrical Currents

Fe–Ni–Si–B metallic glasses have been annealed and crystallized using short electrical current pulses. Two types of electrical heat treatment have been used. The first one is an isothermal annealing treatment using a very high initial heating rate while the second one is a thermal spike applied on an amorphous sample held at various initial temperatures. The microstructure of the alloys after heat treatment has been characterized by x-ray diffraction, transmission electron microscopy, and Mössbauer spectroscopy. The thermal and magnetic properties of the samples measured by DSC and hysteresis loop tracer have been studied after the various heat treatments and correlated with the microstructure of the alloys. The crystallization at high temperatures produces the gamma phase only, while at low temperatures, a mixture of the gamma and alpha phases (the alpha phase being predominant) is usually observed. The samples initially held at liquid nitrogen temperature and heat treated with a thermal spike remain amorphous and show improved magnetic properties (lower coercive field and higher induction at saturation) without loss of ductility.

OCCURRENCE OF SUPERCONDUCTIVITY IN Ca-DOPED (Pb,Cu)Sr2PrCu2Oz

2005 ◽  
Vol 19 (01n03) ◽  
pp. 361-367
Author(s):  
H. K. LEE ◽  
Y. H. KIM ◽  
D. H. HA
Keyword(s):  
Magnetic Properties ◽  
Electrical Resistivity ◽  
Structural Changes ◽  
Hole Doping ◽  
Ca Doping ◽  
Bulk Ceramic ◽  
Electrical And Magnetic Properties ◽  
Ceramic Samples ◽  
Doping Effects ◽  
Occurrence Of Superconductivity

We have investigated the Ca -doping effects on the structural, electrical and magnetic properties of ( Pb 0.5 Cu 0.5) Sr 2( Pr 1-x Ca x Cu 2 O z( x =0-0.5) bulk ceramic samples. The electrical resistivity, thermoelectric power and magnetic susceptibility measurements reveal that the Ca doping introduces holes into the system and thereby superconductivity with onset T c, of about 36 K is induced for a phase with x =0.5. These results are discussed in conjunction with the roles of hole doping, structural changes and Pr - O hybridization in CuO 2 layers.

scholarly journals Structural and Magnetic Properties of Mn Doped BiFeO3 Nanomaterials

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
V. Srinivas ◽  
A. T. Raghavender ◽  
K. Vijaya Kumar
Keyword(s):  
Magnetic Properties ◽  
Doping Concentration ◽  
Structural Changes ◽  
Sol Gel ◽  
Rietveld Analysis ◽  
Ferromagnetic Behavior ◽  
Structural Formation ◽  
Mn Doping ◽  
Structural And Magnetic Properties ◽  
Mn Doped

Nanocrystalline Bi1-xMnxFeO3  (0≤x≤0.3) materials were synthesized using sol-gel technique. The structural and magnetic properties were investigated in detail. Rietveld analysis from XRD revealed the structural formation of BiFeO3. As the Mn doping concentration was increased, the structure of BiFeO3 changed from rhombohedral to tetragonal. All the M-H loops showed the ferromagnetic behavior in the prepared samples. Magnetization was observed to enhance as the Mn doping concentration was increased. The enhanced magnetization may be due to the collapse of the space modulated spin structure as observed from the structural changes.

A series of three-dimensional lanthanide MOFs: Observation of reversible structural changes controlled by solvent desorption–adsorption, and magnetic properties

2011 ◽  
Vol 1004 (1-3) ◽  
pp. 82-87 ◽  
Author(s):  
Sanjit Nayak ◽  
Hari Pada Nayek ◽  
Clemens Pietzonka ◽  
Ghenadie Novitchi ◽  
Stefanie Dehnen
Keyword(s):  
Magnetic Properties ◽  
Structural Changes ◽  
Three Dimensional

Magnetic properties of Cu1+xMxFe2−2xO4 mixed ferrites (M=Ge,Ti, 0⩽x⩽0.4)

2004 ◽  
Vol 269 (2) ◽  
pp. 168-175 ◽  
Author(s):  
A.D Al-Rawas ◽  
A Rais ◽  
A.A Yousif ◽  
A.M Gismelseed ◽  
M.E Elzain ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Mixed Ferrites
Sign in / Sign up

Export Citation Format

Share Document