Adjacent Layer Composition Effects on Fetbco Thin Film Magnetic Properties

1995 ◽  
Vol 384 ◽  
Author(s):  
Michael B. Hintz
Keyword(s):  
Magnetic Properties ◽  
Ion Beam ◽  
Magnetic Layer ◽  
Magnetic Behavior ◽  
Relative Magnitude ◽  
Adjacent Layer ◽  
Energy Product ◽  
Magnetic Layers ◽  
20 Nm ◽  
Layer Composition

ABSTRACTThe magneto-optical (MO) layer in current rare earth-transition metal (RE-TM) based MO recording media is typically 20 nm to 60 nm thick. It has been suggested, however, that media structures employing a multiplicity of thinner MO layers may be advantageous, e.g., for multilevel recording applications [1] or media noise reduction [2]. As magnetic layer thickness is reduced, interactions among magnetic layers and adjacent materials can have an increasingly large influence on magnetic properties; in many instances, these interactions can dominate the observed magnetic behavior.As a means of studying MO layer - adjacent layer interactions, we have used thin (≈3 nm) films of several materials to separate single 24 nm thick ion-beam-deposited FeTbCo layers into N thinner layers of 24/N nm thickness (N × 24/N). As N increases, the FeThCo magnetic properties generally change; however, the relative magnitude of the changes is strongly dependent upon the adjacent layer composition. Magnetization (Ms), energy product (MsHc) at 30 C and Curie temperature data for 1 × 24 nm structures and 6 × 4 nm structures are compared and discussed for specimens employing SiCx, Six, YOx, HfOx, Si and SiOx adjacent layer materials.

Microstructure and Properties of (Tb,Sm)CoSi/Cr Series Thin Films for Permanent Magnets

2007 ◽  
Vol 121-123 ◽  
pp. 267-270 ◽  
Author(s):  
X. Wang ◽  
Z.Y. Li ◽  
X. Yu ◽  
S. Su ◽  
J. Li
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Permanent Magnets ◽  
Magnetic Layer ◽  
Lattice Matching ◽  
Microstructure And Properties ◽  
N2 Atmosphere ◽  
Magnetic Layers

The microstructures and properties of (Tb,Sm)CoSi/Cr series films have been investigated. All the samples were sputtered and annealed at 500 °C for 25 min in pure N2 atmosphere, and their microstructures and properties were examined. The effect on the magnetic properties of partial Sm substituted by Tb is discussed. The lattice matching media were examined. And the mechanisms of interactions among the grains and between the magnetic layers have been analyzed by comparing multi magnetic layer with the mono magnetic layer.

scholarly journals The Magnetic Properties of Fe/Cu Multilayered Nanowires: The Role of the Number of Fe Layers and Their Thickness

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2729
Author(s):  
Sofia Caspani ◽  
Suellen Moraes ◽  
David Navas ◽  
Mariana P. Proenca ◽  
Ricardo Magalhães ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Segment Length ◽  
Magnetic Reversal ◽  
Micromagnetic Simulations ◽  
Cu Nanowires ◽  
Alumina Membranes ◽  
Magnetic Layers ◽  
20 Nm ◽  
Multilayered Nanowires

Multi-segmented bilayered Fe/Cu nanowires have been fabricated through the electrodeposition in porous anodic alumina membranes. We have assessed, with the support of micromagnetic simulations, the dependence of fabricated nanostructures’ magnetic properties either on the number of Fe/Cu bilayers or on the length of the magnetic layers, by fixing both the nonmagnetic segment length and the wire diameter. The magnetic reversal, in the segmented Fe nanowires (NWs) with a 300 nm length, occurs through the nucleation and propagation of a vortex domain wall (V-DW) from the extremities of each segment. By increasing the number of bilayers, the coercive field progressively increases due to the small magnetostatic coupling between Fe segments, but the coercivity found in an Fe continuous nanowire is not reached, since the interactions between layers is limited by the Cu separation. On the other hand, Fe segments 30 nm in length have exhibited a vortex configuration, with around 60% of the magnetization pointing parallel to the wires' long axis, which is equivalent to an isolated Fe nanodisc. By increasing the Fe segment length, a magnetic reversal occurred through the nucleation and propagation of a V-DW from the extremities of each segment, similar to what happens in a long cylindrical Fe nanowire. The particular case of the Fe/Cu bilayered nanowires with Fe segments 20 nm in length revealed a magnetization oriented in opposite directions, forming a synthetic antiferromagnetic system with coercivity and remanence values close to zero.

Cutoff Frequency Study on Nanocrystalline FeNbB Thin Films

2012 ◽  
Vol 465 ◽  
pp. 72-75
Author(s):  
Xiao Long Jiang ◽  
Y.J. Yao ◽  
M. Lai ◽  
K. Peng ◽  
Y.W. Du
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Ion Beam ◽  
Cutoff Frequency ◽  
Magnetic Behavior ◽  
Soft Magnetic Properties ◽  
Ion Beam Sputtering ◽  
Soft Magnetic ◽  
Beam Sputtering

A series of nanocrystalline FeNbB films were fabricated using ion-beam sputtering technique from FeNbB target. Pieces of these films were annealed for 1 hour at various temperatures up to 5730C. Room temperature soft magnetic properties of these films were measured. The influence of microstructure on magnetic behavior in nanocrystalline FeNbB films is investigated in a series of specimens with different film’s thickness. For the sample 120nm and 5000C annealed, cutoff frequency was found to be 5E7 Hz, which has the μf0=5E10.

APPLIED SURFACE AND PROPERTIES ANALYSES OF Co-BASED NANOPARTICLE THIN FILMS FOR PERMANENT MAGNETS

2006 ◽  
Vol 05 (06) ◽  
pp. 821-826
Author(s):  
XIANG WANG ◽  
ZUOYI LI
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Permanent Magnets ◽  
Magnetic Layer ◽  
Perpendicular Anisotropy ◽  
Transition Metal Alloy ◽  
Lattice Matching ◽  
Fine Grain ◽  
Magnetic Layers

The SmCoSi/Cr layers were sputtered and annealed at 500°C for 25 min in pure N 2 atmosphere. The optimum value of coercivity of 4.6 kOe and extremely fine grain size of average grain diameter 6.5 nm, or small switching volume V* of 2.6 × 10-19 cm 3 were obtained. Partial Sm substituted by Tb will directly affect the magnetic properties. The ( Sm 0.32 Tb 0.68) Co 2 Si 3/ Cr layers with perpendicular anisotropy have been investigated. Their values of magnetization Ms as high as 402 emu/cm3 and coercivity Hc above 5.5 kOe at room temperature were gotten. These films are the ferri-magnetical structure of the rare earth-transition metal alloy. The microstructures and lattice matching media were examined, and the mechanisms of decoupling intergrains within the same magnetic layer, and among magnetic layers have been analyzed.

Magnetic Properties of Co Thin Films Evaporated under Normal and Oblique Incidence

2014 ◽  
Vol 215 ◽  
pp. 288-291 ◽  
Author(s):  
Ahmed Kharmouche
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Thick Film ◽  
Oblique Incidence ◽  
Magnetic Layer ◽  
Anisotropy Field ◽  
Gradient Field ◽  
Cobalt Films ◽  
20 Nm ◽  
Deposition Angle

We have evaporated series of Co thin films under vacuum onto silicon and glass substrates at a perpendicular and oblique incidence. The thickness of the magnetic layer ranges from 20 to 400 nm. The static magnetic properties have been performed by means of magnetic force microscopy (M.F.M.) and Alternating Gradient Field Magnetometer (A.G.F.M.) techniques. The influence of the magnetic layer thickness and the deposition angle are studied. As results, it is found a decrease of the coercive field from 250 Oe, for t = 20 nm, to 95 Oe, for t = 400 nm. TheseHcvalues for obliquely evaporated cobalt films are larger than those measured for cobalt films evaporated at normal incidence, found to be equal to a few Oe. It is also found a decrease of the anisotropy field, from 1.6 kOe for the 20 nm Co thick film to 0.95 kOe for the 200 nm Co thick film. Furthermore, an increase of these fields with the increase of the deposition angle is found, as well. The easy axis of the saturation magnetization lies in the film plane, irrespective of the substrate nature. These results, and others, are presented and discussed.

Structure and Magnetic Properties of Strontium Hexaferrite Nanopowders Prepared by Mechanochemical Synthesis

2006 ◽  
Vol 45 ◽  
pp. 321-326 ◽  
Author(s):  
Cornel Miclea ◽  
Constantin Tanasoiu ◽  
Corneliu Florin Miclea ◽  
I. Spanulescu ◽  
Anca Gheorghiu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Mechanochemical Synthesis ◽  
Milled Powder ◽  
Magnetic Behavior ◽  
High Energy ◽  
Strontium Hexaferrite ◽  
Synthesis Process ◽  
Energy Product ◽  
Suitable Heat Treatment ◽  
Structural Deformations

Strontium hexaferrite nanopowders were prepared by mechanochemical synthesis from strontium and iron oxides using a high energy ball mill after 50 hours of milling. The synthesis process was checked by X-Ray diffractograms on powders milled for different times. The magnetic properties of hexaferrite nanopowder, both compacted and dispersed in a nonmagnetic matrix were determined. Severe stresses and structural deformations were introduced by mechanical processing, but they were eliminated, to a great extent, by a suitable heat treatment of the milled powder at 1000 oC for one and a half hour. Coercivities as high as 6600 Oe and specific magnetization of 65 emu/g were found for annealed noninteracting nanopowders. Such values are very near to the theoretical values for strontium ferrite. The magnetic behavior of such powders can be rather well described by the coherent rotation model of Stoner-Wohlfarth for an assembly of single domain particles oriented at random. Sintered bodies of such powders produced magnets with a high HC of 4600 Oe, a Br of 2100 Gs and an energy product maxim of approximately 1.85 MGOe.

Effect of Binders on the Magnetic Behavior of P/M Processed FeSiBCuNb Alloy

2004 ◽  
Vol 449-452 ◽  
pp. 501-504 ◽  
Author(s):  
Hee Jin Kim ◽  
Yong Sul Song ◽  
Won Wook Park ◽  
Keun Yong Sohn
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Magnetic Behavior ◽  
Hammer Mill ◽  
Amorphous Ribbons ◽  
Polymer Binders ◽  
Annealed Ribbon ◽  
20 Nm ◽  
Maximum Permeability

The effect of heat treatment and binder additions on the magnetic behavior of P/M(powder metallurgy) processed Fe73.5Si13.5B9Cu1Nb3 alloy has been investigated. FeSiBCuNb amorphous ribbons produced by plannar flow casting were annealed at temperatures between 480°C and 620°C for 20 to 60 minutes. The annealed specimens were milled using a pin crusher and a hammer mill. The powder was then mixed with mineral or polymer binders to press into a toroidal shape of inductor core at room temperature. Fe73.5Si13.5B9Cu1Nb3 alloy showed maximum permeability when annealed at 540°C for 40 minutes. The microstructure of the annealed ribbon has a ultra-fine α-Fe(Si) grain, ranging from 10 to 20 nm in diameter. Inductor cores produced using a glass binder showed better magnetic properties than polymers or oxide binders. The use of mineral binders in producing nanocrystalline inductor cores significantly improved magnetic properties, compared to a commercial moly-permalloy powder core.

Lorentz electron microscopy of magnetic domains in rapidly solidified and annealed Pt-Co-B alloys

1991 ◽  
Vol 49 ◽  
pp. 784-785
Author(s):  
N. Qiu ◽  
J. E. Wittig
Keyword(s):  
Rapid Solidification ◽  
Ion Beam ◽  
Magnetic Behavior ◽  
High Coercivity ◽  
Magnetic Domains ◽  
Beam Angle ◽  
Tem Analysis ◽  
Intrinsic Coercivity ◽  
Hard Magnets ◽  
Rapidly Solidified

PtCo hard magnets have specialized applications owing to their relatively high coercivity combined with corrosion resistance and ductility. Increased intrinsic coercivity has been recently obtained by rapid solidification processing of PtCo alloys containing boron. After rapid solidification by double anvil splat quenching and subsequent annealing for 30 minutes at 650°C, an alloy with composition Pt42Co45B13 (at.%) exhibited intrinsic coercivity up to 14kOe. This represents a significant improvement compared to the average coercivities in conventional binary PtCo alloys of 5 to 8 kOe.Rapidly solidified specimens of Pt42Co45B13 (at.%) were annealed at 650°C and 800°C for 30 minutes. The magnetic behavior was characterized by measuring the coercive force (Hc). Samples for TEM analysis were mechanically thinned to 100 μm, dimpled to about 30 nm, and ion milled to electron transparency in a Gatan Duomill at 5 kV and 1 mA gun current. The incident ion beam angle was set at 15° and the samples were liquid nitrogen cooled during milling. These samples were analyzed with a Philips CM20T TEM/STEM operated at 200 kV.

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

Low Energy Ar Ion Milling of FIB TEM Specimens from 14 nm and Future FinFET Technologies

2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione
Keyword(s):  
Field Effect Transistor ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Ion Milling ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Effect Transistor ◽  
20 Nm ◽  
Argon Ion

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.

Sign in / Sign up

Export Citation Format

Share Document