ELECTRICAL PROPERTIES OF Cd2+ SUBSTITUTED Li–Zn FERRITES

2010 ◽  
Vol 24 (20) ◽  
pp. 2195-2200 ◽  
Author(s):  
MAMATA MAISNAM ◽  
SUMITRA PHANJOUBAM ◽  
CHANDRA PRAKASH
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Curie Temperature ◽  
Lattice Constant ◽  
Spinel Structure ◽  
Single Phase ◽  
Dc Resistivity ◽  
Constant Density ◽  
Zn Ferrite

Cd 2+ substituted Li – Zn ferrite with compositional formula Li 0.4-x/2 Zn 0.2 Cd x Fe 2.4-x/2 O 4 with x = 0.02, 0.03 and 0.04 were prepared by the conventional double sintering ceramic technique. XRD technique confirmed the formation of single phase with spinel structure. The substitution causes an increase in the lattice constant, density and DC resistivity, while the Curie temperature and dielectric constant decreases with Cd 2+ substitution. The mechanisms involved are discussed.

DIELECTRIC PROPERTIES OF Ni2+ AND Mn3+ SUBSTITUTED Li-FERRITE PREPARED BY MICROWAVE SINTERING TECHNIQUE

2007 ◽  
Vol 21 (08) ◽  
pp. 497-503 ◽  
Author(s):  
MAMATA MAISNAM ◽  
SUMITRA PHANJOUBAM ◽  
H. N. K. SARMA ◽  
L. RADHAPIYARI DEVI ◽  
O. P. THAKUR ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Electrical Properties ◽  
Comparative Study ◽  
Lattice Constant ◽  
Spinel Structure ◽  
Single Phase ◽  
Microwave Sintering ◽  
Dielectric Behavior ◽  
Phase Spinel ◽  
Xrd Studies

Li 0.45 Ni 0.1 Mn 0.1 Fe 2.35 O 4 ferrite samples were prepared by microwave-sintering (MS) and conventional (CS) techniques. XRD studies have confirmed the single-phase spinel structure of the sample. The lattice constant was found to be 8.334 Å which is lower than that of the conventionally sintered (CS) sample. Upon microwave sintering, improved physical and electrical properties (like density, resistivity etc.) were obtained. A comparative study has been made on the dielectric behavior of samples processed by both techniques. The possible mechanisms are discussed.

Dielectric Properties of Vanadium Substituted Lithium Zinc Titanium Ferrites

2003 ◽  
Vol 17 (21) ◽  
pp. 3881-3887 ◽  
Author(s):  
Mamata Maisnam ◽  
Sumitra Phanjoubam ◽  
H. N. K. Sarma ◽  
O. P. Thakur ◽  
L. Radhapiyari Devi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Curie Temperature ◽  
Saturation Magnetization ◽  
Spinel Structure ◽  
Single Phase ◽  
Xrd Analysis ◽  
Dielectric Behaviour ◽  
Conventional Sintering ◽  
Vanadium Substitution

This paper reports the influence of vanadium substitution on the properties of Li – Zn – Ti ferrite. Samples with compositional formula Li 0.5+t Zn 0.2 Ti 0.2 V t Fe 2.1-2t O 4 (t ranging from 0 to 0.25 in steps of 0.05) were prepared by the conventional sintering technique. XRD analysis confirmed all the samples to be single phase with spinel structure. The lattice constant a density, Curie temperature and Saturation magnetization were measured. The dielectric behaviour was studied as a function of frequency and temperature. The dielectric behaviour showed dispersion with the frequency in the range 100 Hz to 1 MHz. The dielectric constant increases with the increase of temperature for all the samples. The possible mechanisms involved are discussed.

ELECTRICAL CONDUCTION IN SUBSTITUTED Li-FERRITES PREPARED BY MICROWAVE PROCESSING

2005 ◽  
Vol 19 (21) ◽  
pp. 1051-1055 ◽  
Author(s):  
MAMATA MAISNAM ◽  
SUMITRA PHANJOUBAM ◽  
H. N. K. SARMA ◽  
CHANDRA PRAKASH ◽  
L. RADHAPIYARI DEVI ◽  
...  
Keyword(s):  
Activation Energy ◽  
Lattice Constant ◽  
Electrical Conduction ◽  
Spinel Structure ◽  
Single Phase ◽  
Microwave Sintering ◽  
Microwave Processing ◽  
Conventional Sintering

Samples with representative formula Li 0.45 Ni 0.1 Mn 0.1 Fe 2.35 O 4 have been sintered by conventional sintering technique and microwave sintering technique. Both the samples showed single-phase with spinel structure. The lattice constant for the microwave sintered (MS) sample showed a lower value than the conventionally sintered (CS) sample. The density of the MS sample has been found to be higher than the CS sample. And MS sample showed a higher value of resistivity and activation energy compared to the CS sample. The possible mechanisms are discussed.

Study on Microstructure and Properties of BTBY Piezoelectric Ceramics with High Curie Temperature

2010 ◽  
Vol 156-157 ◽  
pp. 1541-1544
Author(s):  
Bo Li ◽  
Feng Gao ◽  
Liang Liang Liu ◽  
Bei Xu
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Curie Temperature ◽  
Grain Morphology ◽  
High Curie Temperature ◽  
Microstructure And Properties ◽  
New Phase ◽  
Dielectric Relaxor

(1-x)(0.6BIT-0.4BT)-xBiYbO3(BTBY) ceramics with high Curie temperature were prepared by the conventional processing. The effect of BiYbO3 content on the microstructure and electrical properties was investigated. The results show that the main phase of BTBY ceramics is BIT-BT, and a new phase BaBi4Ti4O15 (BBT) appeared. The grain morphology of BTPY ceramics are platelike and the grain size was significantly increased with increasing content of BiYbO3 .Tc of all the BTBY samples are above 440 . The BTBY ceramics show obvious dielectric relaxor characteristic. The dispersion factor γ, the dielectric constant εr, and the dielectric loss tanδ decreased with increasing the content of BiYbO3. When the content of BiYbO3 is 0.06, the optimal properties of BTBY ceramics are obtained, Tc is 457 , εr is 165, tanδ is 0.0223 and d33 is 10 pC·N-1.

scholarly journals Influence of V2O5 Addition on the Magnetic and Electrical Properties of Iron-Deficient Ni-Zn Ferrite

1970 ◽  
Vol 33 (2) ◽  
pp. 145-149 ◽  
Author(s):  
Shireen Akther ◽  
Md Amanullah Choudhury ◽  
Jalalur Rahman
Keyword(s):  
Electrical Properties ◽  
Curie Temperature ◽  
Saturation Magnetization ◽  
Vacancy Concentration ◽  
Anion Vacancy ◽  
Ferrite Matrix ◽  
Iron Deficient ◽  
Zn Ferrite ◽  
Academy Of Sciences ◽  
Magnetic And Electrical Properties

The influence of V2O5 addition on the magnetic and electrical properties of iron deficient ferrites with composition: Ni0.65Zn0.35Fe1.96O4+xV2O5 have been investigated, where values of x (in mol unit) are 0, 0.002, 0.004, 0.006, 0.008 and 0.01. The sintered density, saturation magnetization, Curie temperature of the samples increase up to V2O5 (x=0.004) and then decrease. The addition of V2O5 to the composition of ferrite increases the anion vacancy concentration, prohibit the discontinuous grain growth, which in turn enhances the density. The increment of saturation magnetization is due to the enhancement of resultant sublattice magnetic moment and density. Upto V2O5 (x=0.004), V2O5 goes into solid solution with the ferrite matrix and increases the Curie temperature. This is probably due to ions occupy some octahedral sites (B-sites) of the ferrite lattice by V5+ , as a result some Fe3+ ions may come out from octahedral to tetrahedral sites (A-sites) thereby increasing A-B interaction and hence the Curie temperature. The dc resistivity of all the samples increases with the increment of V2O5 in the compound. DOI: 10.3329/jbas.v33i2.4097 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 145-149, 2009

scholarly journals Effect on Magnetic Properties of Zinc Doped Nano Ferrites Synthesized by Precursor or Method

2013 ◽  
Vol 19 ◽  
pp. 37-43 ◽  
Author(s):  
T. Anjaneyulu ◽  
P. Narayana Murthy ◽  
S.M. Rafi ◽  
S. Bademiya ◽  
G. Samuel John
Keyword(s):  
Spinel Structure ◽  
Single Phase ◽  
Sem Analysis ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Zn Doping ◽  
Zn Ferrite ◽  
Phase Spinel ◽  
Ir Analysis ◽  
Zn Ions

Nanocrystalline Cu-Zn ferrites have been synthesized using precursor method. Cu-Zn ferrites were formed at low temperature without any impurities. The particle sizes were observed to decrease from 60 nm to 50 nm with increasing non-magnetic Zn doping. Cu is used to decrease the sintering temperature. The X-ray diffraction (XRD) and IR analysis of Cu-Zn revealed the formation of Single-Phase Spinel structure at very low annealing temperature. The particle sizes observed from XRD is very well in agreement with SEM analysis. Cu-Zn ferrite nanoparticles were observed to be dependent on the particle size. Saturation (Ms) and Remanence (Mr) magnetization of ferrites increases due to the modifications occurred among the A-B, A-A and B-B interactions of Spinel structure. The Coercive force (Hc) decreases with increase of Zn ions concentration.

Investigation of the in situ calcination of aerosol co-deposited NiO-Mn2O3 films

2019 ◽  
Vol 12 (03) ◽  
pp. 1950039 ◽  
Author(s):  
Michaela Schubert ◽  
Jaroslaw Kita ◽  
Christian Münch ◽  
Ralf Moos
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Spinel Structure ◽  
Single Phase ◽  
Electrical Measurements

An in situ calcination of an aerosol co-deposited (AcD) NiO-Mn2O3 film for the production of a single-phase cubic NiMn2O4 spinel film was investigated. Characterizations of the AcD film were performed before, during, and after calcination using SEM, XRD and electrical measurements. It could be shown that in situ calcination to mechanically stable films with single-phase cubic spinel structure is possible. Furthermore, changes in the crystal structure and the NTCR parameters [Formula: see text] and [Formula: see text] during calcination could be shown. After in situ calcination, the electrical properties are similar to those of conventional bulk ceramics.

scholarly journals Dielectric Properties, Resistivity and Curie temperature Of Co doped CdNi perminvar ferrite

1970 ◽  
Vol 32 (1) ◽  
pp. 23-32 ◽  
Author(s):  
DK Saha ◽  
MA Hakim
Keyword(s):  
Dielectric Constant ◽  
Curie Temperature ◽  
Single Phase ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Two Samples ◽  
Good Consistency ◽  
Increasing Temperature ◽  
Academy Of Sciences

CdNi perminvar ferrites doped with Co were prepared through the solid-state reaction using conventional ceramic technique. The compositions of the ferrite were Co0.02Cd0.20Ni0.58Fe2.2O4 and Co0.02Cd0.28Cd0.28Ni0.50Fe2.2O4. X-ray diffraction study of the samples indicates the single phase of perminvar ferrites. Lattice parameter of the samples was found to be 8.3676 and 8.4249 Å for sample no. (a) of Co0.02Cd0.20Ni0.58Fe2.2O4 and sample no. (b) of Co0.02Cd0.28Ni0.50Fe2.2O4, respectively. The porosity of the samples was found to be 10.03 and 9.53%. The values of Curie temperature for the two samples were found to be 472 ± 1 and 405 ± 1°C, respectively. Resistivity of the samples was measured from room temperature up to 600°C. At 30°C resistivity was found to be 334 and 456 ohm-cm, respectively. Frequency dependent dielectric constant for the two samples has been determined from the experimental capacitance values. The value of dielectric constant at frequency, f = 1 kHz and sintering temperature Ts = 1250°C was found to be 16.6 × 106 and 56.1 × 106, for sample no. (a) and (b), respectively. Dielectric constant was observed 3.5 times higher in the Cd rich sample of Co0.02Cd0.28Ni0.50Fe2.2O4 and Co0.02Cd0.20Ni0.58Fe2.2O4. Temperature dependent dielectric constant has been measured for the samples in the temperature range of 30 - 250°C. The value of dielectric constant initially increases slowly with increasing temperature and then rises sharply until reaching a certain temperature, then it begins to decrease with further increase of temperature. Anomalies in the resistivity curves have good consistency with the temperature dependent dielectric constant and Curie temperature values. doi: 10.3329/jbas.v32i1.2438 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 23-32, 2008

Structure Ordering in Mg-Zn Ferrite Nanopowders Obtained by the Method of Sol-Gel Autocombustion

2015 ◽  
Vol 230 ◽  
pp. 114-119 ◽  
Author(s):  
A.V. Kopayev ◽  
V.V. Mokljak ◽  
I.M. Gasyuk ◽  
I.P. Yaremiy ◽  
V.V. Kozub
Keyword(s):  
Spinel Structure ◽  
Single Phase ◽  
Sol Gel ◽  
Structural Heterogeneity ◽  
Phase System ◽  
Structural Components ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Zn Ferrite

The Mg1-xZnxFe2O4 (x = 0, 0.2, 0.44, 0.5, 0.6) ferrite nanopowders of the spinel structure obtained by the sol-gel autocombustion (SGA) have been investigated using the X-ray diffraction and Mössbauer methods. The proofs were revealed verifying the potential occurrence of structural heterogeneity as solid solutions of various compositions of ferrites can be observed in a single phase system. In case of magnesium–zinc replacement, structural components occur, having different distribution of ferrum cations in crystallographic positions of the spinel lattice. The abnormal strength of nuclear effective fields is the indicator thereof. In addition, paramagnetic and superparamagnetic components were discovered there as well. This effect cannot be observed in the ferrite synthesis by the ceramic method.

Enhancement in Curie Temperature with Magnesium Substituted in Sintered MgxMn1-xFe2O4 Pellets of Nanopowders

2016 ◽  
Vol 43 ◽  
pp. 38-45 ◽  
Author(s):  
Sohrab Manouchehri ◽  
Seyed Taghi Mohammadi Benehi ◽  
Mohammad Hassan Yousefi
Keyword(s):  
Curie Temperature ◽  
Lattice Constant ◽  
Single Phase ◽  
Lattice Models ◽  
Substitution Effect ◽  
Magnesium Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Trend ◽  
Single Phase Formation

Ferrites nanopowder of spinel MgxMn1-xFe2O4 (with x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) synthesized by the coprecipitation method and pellets of nanopowder sintered at temperature 1250 °C. The X-ray diffraction results confirmed the single phase formation of the samples. The lattice constant and interionic distances decreased with increase in magnesium content that can be originated by strengthening of A–B interaction. The substitution effect of nonmagnetic Mg2+ ions was studied on Curie temperature of sintered pellets. Curie temperature measurements exhibit increasing trend with increase in magnesium content. Enhancement in Curie temperature can be explained on the basis of strengthening of A–B interaction and Neel’s two sub-lattice models.

Sign in / Sign up

Export Citation Format

Share Document