The Influence of Composition on Morphology, Structure and Magnetic Properties of Ni-Co Films on Aluminum Prepared by Electroplating Method

In this paper, Ni-Co alloy films with different composition were obtained by means of electroplating method. The morphology, structure and magnetic properties of Ni-Co alloy films with different Cobalt content are evaluated. The effect of the crystal orientation on the morphology of Ni-Co deposits with different compositon was discussed. The results showed that Ni–Co alloy films with Cobalt content decrease is composed of pyramidal, spindly, mixed pyramidal and spindly, and cellular particles respectively. To the deposits with similar composition, change of morphology is related to the preferential orientation. With the increase of the Nickel content, the saturation magnetization (Ms) value of the Ni–Co alloy films increases and then decreases sharply. The coercivety (Hc) value of the Ni–Co alloy films decreases with the Nickel content increase.

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Effect of pH on Composition, Structure and Magnetic Properties of Electrodeposited Co-Ni Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.68.52 ◽

2009 ◽

Vol 68 ◽

pp. 52-59 ◽

Cited By ~ 5

Author(s):

T. Mahalingam ◽

K. Sundaram ◽

Subramaniam Velumani ◽

M. Raja ◽

S. Thanikaikarasan ◽

...

Keyword(s):

Magnetic Properties ◽

Nickel Content ◽

Cobalt Content ◽

Soft Magnetic ◽

Solution Ph ◽

Ni Alloys ◽

Ni Alloy ◽

Sulfate Baths ◽

Composition Structure ◽

Kinetics Of

Co-Ni alloy thin films were electrodeposited from sulfate baths at various solution pH values (1.5-5.5) ±0.1. The deposition kinetics of the films was studied using linear sweep voltametry (LSV). XRD studies exhibited fcc and hcp phases for Co-Ni alloys deposited at low and high pH ranges, respectively. EDAX studies showed that the cobalt content increased and nickel content decreased with increase in solution pH. The surface morphology of Co-Ni films were analyzed by scanning electron microscopy. It is found that the Co-Ni alloys synthesized at low pH exhibited soft magnetic properties and the films deposited at higher values revealed hard magnetic properties and the results are discussed.

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Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.210 ◽

2017 ◽

Vol 8 ◽

pp. 2106-2115 ◽

Cited By ~ 14

Author(s):

Soraya Sangiao ◽

César Magén ◽

Darius Mofakhami ◽

Grégoire de Loubens ◽

José María De Teresa

Keyword(s):

Magnetic Properties ◽

Electron Beam ◽

Saturation Magnetization ◽

Magnetic Hysteresis ◽

Hysteresis Loops ◽

Cobalt Content ◽

Vortex State ◽

Magnetic Vortex ◽

Electron Holography ◽

Electron Beam Induced Deposition

In this work, we present a detailed investigation of the magnetic properties of cobalt nanospheres grown on cantilever tips by focused electron beam induced deposition (FEBID). The cantilevers are extremely soft and the cobalt nanospheres are optimized for magnetic resonance force microscopy (MRFM) experiments, which implies that the cobalt nanospheres must be as small as possible while bearing high saturation magnetization. It was found that the cobalt content and the corresponding saturation magnetization of the nanospheres decrease for nanosphere diameters less than 300 nm. Electron holography measurements show the formation of a magnetic vortex state in remanence, which nicely agrees with magnetic hysteresis loops performed by local magnetometry showing negligible remanent magnetization. As investigated by local magnetometry, optimal behavior for high-resolution MRFM has been found for cobalt nanospheres with a diameter of ≈200 nm, which present atomic cobalt content of ≈83 atom % and saturation magnetization of 106 A/m, around 70% of the bulk value. These results represent the first comprehensive investigation of the magnetic properties of cobalt nanospheres grown by FEBID for application in MRFM.

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Investigation and Effective Control of Perpendicular Magnetic Anisotropy for TbCo Films with Different Underlayers

SPIN ◽

10.1142/s2010324716500090 ◽

2016 ◽

Vol 06 (03) ◽

pp. 1650009 ◽

Cited By ~ 2

Author(s):

Minghong Tang ◽

Shaohai Chen ◽

Xiangli Zhang ◽

Zongzhi Zhang ◽

Q. Y. Jin

Keyword(s):

Magnetic Properties ◽

Magnetic Anisotropy ◽

Saturation Magnetization ◽

Magnetic Moments ◽

Perpendicular Magnetic Anisotropy ◽

Effective Control ◽

Experimental Measurements ◽

Alloy Films ◽

Micromagnetic Simulations

We performed a detailed study on the perpendicular magnetic anisotropy (PMA) of TbCo film by using two kinds of nonmagnetic underlayers, Ta and Ta/Cu with different thicknesses. We found that for both the Tb-rich and Co-rich TbCo alloy films, the PMA strength decreases considerably with the increase of Ta underlayer thickness, while their net saturation magnetization [Formula: see text] exhibit opposite varying trends. The [Formula: see text] value continues to increase for the Co-rich TbCo samples while decrease for the Tb-rich films. Interestingly, an additional Cu layer inserted between the Ta and TbCo layers can efficiently recover the PMA and [Formula: see text]. We attribute such observed variation behaviors of magnetic properties to the increased disordering of Tb magnetic moments at the Ta/TbCo interface, which has been verified by both experimental measurements and micromagnetic simulations.

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Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681208666181018093813 ◽

2020 ◽

Vol 10 (2) ◽

pp. 152-156 ◽

Cited By ~ 1

Author(s):

Muhammad Hanif bin Zahari ◽

Beh Hoe Guan ◽

Lee Kean Chuan ◽

Afiq Azri bin Zainudin

Keyword(s):

Magnetic Properties ◽

Rare Earth ◽

Saturation Magnetization ◽

Sol Gel ◽

Magnetic Behavior ◽

Rare Earth Ions ◽

Ion Concentration ◽

Zn Ferrite ◽

Auto Combustion ◽

Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

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The Structure and Magnetic Properties of NiZn-Ferrite Films Deposited by Magnetron Sputtering at Room Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1702 ◽

2013 ◽

Vol 690-693 ◽

pp. 1702-1706 ◽

Cited By ~ 2

Author(s):

Shuang Jun Nie ◽

Hao Geng ◽

Jun Bao Wang ◽

Lai Sen Wang ◽

Zhen Wei Wang ◽

...

Keyword(s):

Thin Films ◽

Magnetic Properties ◽

Magnetron Sputtering ◽

Saturation Magnetization ◽

Room Temperature ◽

Oxygen Flow ◽

Flow Ratio ◽

Study Results ◽

Ferrite Thin Films ◽

Ferrite Films

NiZn-ferrite thin films were deposited onto silicon and glass substrates by radio frequency magnetron sputtering at room temperature. The effects of the relative oxygen flow ratio on the structure and magnetic properties of the thin films were investigated. The study results reveal that the films deposited under higher relative oxygen flow ratio show a better crystallinity. Static magnetic measurement results indicated that the saturation magnetization of the films was greatly affected by the crystallinity, grain dimension, and cation distribution in the NiZn-ferrite films. The NiZn-ferrite thin films with a maximum saturation magnetization of 151 emucm-3, which is about 40% of the bulk NiZn ferrite, was obtained under relative oxygen flow ratio of 60%.

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Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Nanomaterials ◽

10.3390/nano11051231 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1231

Author(s):

Venkatesha Narayanaswamy ◽

Imaddin A. Al-Omari ◽

Aleksandr S. Kamzin ◽

Bashar Issa ◽

Huseyin O. Tekin ◽

...

Keyword(s):

Magnetic Properties ◽

Field Strength ◽

Saturation Magnetization ◽

Absorption Rate ◽

Specific Absorption Rate ◽

Ferrite Nanoparticles ◽

Cofe2o4 Nanoparticles ◽

Specific Absorption ◽

Octahedral Sites ◽

Mixed Ferrite

Mixed ferrite nanoparticles with compositions CoxMn1-xFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by a simple chemical co-precipitation method. The structure and morphology of the nanoparticles were obtained by X-ray diffraction (XRD), transmission electron microscope (TEM), Raman spectroscopy, and Mössbauer spectroscopy. The average crystallite sizes decreased with increasing x, starting with 34.9 ± 0.6 nm for MnFe2O4 (x = 0) and ending with 15.0 ± 0.3 nm for CoFe2O4 (x = 1.0). TEM images show an edge morphology with the majority of the particles having cubic geometry and wide size distributions. The mixed ferrite and CoFe2O4 nanoparticles have an inverse spinel structure indicated by the splitting of A1g peak at around 620 cm−1 in Raman spectra. The intensity ratios of the A1g(1) and A1g(2) peaks indicate significant redistribution of Co2+ and Fe3+ cations among tetrahedral and octahedral sites in the mixed ferrite nanoparticles. Magnetic hysterics loops show that all the particles possess significant remnant magnetization and coercivity at room temperature. The mass-normalized saturation magnetization is highest for the composition with x = 0.8 (67.63 emu/g), while CoFe2O4 has a value of 65.19 emu/g. The nanoparticles were PEG (poly ethylene glycol) coated and examined for the magneto thermic heating ability using alternating magnetic field. Heating profiles with frequencies of 333.45, 349.20, 390.15, 491.10, 634.45, and 765.95 kHz and 200, 250, 300, and 350 G field amplitudes were obtained. The composition with x = 0.2 (Co0.2Mn0.8Fe2O4) with saturation magnetization 57.41 emu/g shows the highest specific absorption rate (SAR) value of 190.61 W/g for 10 mg/mL water dispersions at a frequency of 765.95 kHz and 350 G field strength. The SAR values for the mixed ferrite and CoFe2O4 nanoparticles increase with increasing concentration of particle dispersions, whereas for MnFe2O4, nanoparticles decrease with increasing the concentration of particle dispersions. SARs obtained for Co0.2Mn0.8Fe2O4 and CoFe2O4 nanoparticles fixed in agar ferrogel dispersions at frequency of 765.95 kHz and 350 G field strength are 140.35 and 67.60 W/g, respectively. This study shows the importance of optimizing the occupancy of Co2+ among tetrahedral and octahedral sites of the spinel system, concentration of the magnetic nanoparticle dispersions, and viscosity of the surrounding medium on the magnetic properties and heating efficiencies.

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