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The magnetic and magnetotransport properties of Ni80Fe20/La0.7Sr0.3MnO3 (NiFe/LSMO) bilayers were investigated after bombarding the LSMO surface with low-energy Ar+ or O2+/Ar+ ion beams before the growth of the top NiFe layer. A variety of magnetic properties are revealed, including an asymmetric two-stepped hysteresis loop with an exchange bias loop shift, and alternatively, a symmetric two-stepped hysteresis loop with an enhanced coercivity. Polarized neutron reflectometry measurements provide details of the magnetic depth profile and interface layer magnetism at different temperatures. The LSMO surface modifications determine a complex magnetic and electric NiFe/LSMO interface having a strong effect on the magnetoresistance of the bilayer. Surface engineering based on ion beam bombardment is presented as a promising technique for optimizing the electronic and magnetic properties of NiFe/LSMO junctions for future device applications. [ABSTRACT FROM AUTHOR]

Processed meats normally contain more fat than whole muscle products, but lowering the fat content in some products has resulted in increased toughness. A new study investigates the effects of including carrageenan, alginate or soy protein isolate on the functionality of salt-soluble proteins and the physicochemical properties of low-fat meat batters heated to different temperatures. The study shows that adding gums and soy protein isolates to reduced fat meat batter could improve its emulsion stability and water-holding capacity.

We have fabricated thin films of iron nanocrystallites embedded in a copper matrix using a dual ion beam assisted deposition technique. A secondary End-Hall ion beam bombarded the iron atoms during deposition altering significantly the morphology of the films and allowing for control of the intermixing between iron and copper components. Cross-sectional transmission electron microscopy and x-ray reflectometry experiments indicated that the morphology of the films was that of iron nanocrystallites embedded in a copper matrix. Rietveld refinements of the diffraction pattern identified fcc-copper and amorphous iron. An increased amount of disorder was observed with a reduction in the amount of deposited iron from a 1:1 Fe:Cu ratio to 0.25:0.75 Fe:Cu ratio. Interfacial copper-iron alloys were identified by DC susceptibility experiments through their reduced TC,Alloy (370, 310, and 280 K) compared with that of bulk iron (~1000 K). Element specific x-ray absorption and x-ray magnetic circular dichroism experiments were performed to identify the contributions to the magnetism from the iron and the copper-iron alloy. [ABSTRACT FROM AUTHOR]

Ni3Fe/(Ni, Fe)O thin films with bilayer and nanocrystallite dispersion morphologies are prepared with a dual ion beam deposition technique permitting precise control of nanocrystallite growth, composition, and admixtures. A bilayer morphology provides a Ni3Fe-to-NiO interface, while the dispersion films have different mixtures of Ni3Fe, NiO, and FeO nanocrystallites. Using detailed analyses of high resolution transmission electron microscopy images with Multislice simulations, the nanocrystallites' structures and phases are determined, and the intermixing between the Ni3Fe, NiO, and FeO interfaces is quantified. From field-cooled hysteresis loops, the exchange bias loop shift from spin interactions at the interfaces are determined. With similar interfacial molar ratios of FM-to-AF, we find the exchange bias field essentially unchanged. However, when the interfacial ratio of FM to AF was FM rich, the exchange bias field increases. Since the FM/AF interface 'contact' areas in the nanocrystallite dispersion films are larger than that of the bilayer film, and the nanocrystallite dispersions exhibit larger FM-to-AF interfacial contributions to the magnetism, we attribute the changes in the exchange bias to be from increases in the interfacial segments that suffer defects (such as vacancies and bond distortions), that also affects the coercive fields. [ABSTRACT FROM AUTHOR]

The strength, polarity, and temperature dependence of the exchange bias field in ferromagnet/antiferromagnet thin film systems depend critically on the nature of the interfacial microstructure. Using ion bombardment during film deposition, we have found a way to modulate the interface microstructure, providing unique control over the exchange bias magnetism. We demonstrate interfacial microstructure modulation in Ni80Fe20/(Ni,Fe)O thin films, where different ion bombardment energies alter the exchange coupling between the (Ni,Fe)O and Ni80Fe20 interfaces. One interface configuration provides positive or negative exchange coupling depending on whether the film was cooled with or without an external magnetic field, while another interface configuration results in the more typical negative exchange coupling independent of the field cooling. [ABSTRACT FROM AUTHOR]

The exchange bias field dependence on the Mn-oxide and its microstructure in NiFe/Mn-oxide bilayers was investigated. Transmission electron microscopy results have shown that the bilayer bottom consisted of either α-Mn, rocksalt MnO, or a composite of tetragonal Mn3O4+MnO, depending on the ratio of O2/Ar used during dual ion-beam deposition. Magnetometry results at 5 K indicate that the exchange bias field (Hex∼-300 Oe) is largest in a NiFe/Mn (0%O2/Ar) bilayer. The MnO formation by in situ Mn oxidation results in a decrease in Hex in a NiFe/Mn-oxide (21%O2/Ar) bilayer. In contrast, a further increase in the O2/Ar ratio during deposition results in larger Hex and Hc. This is attributed to the oxidation of MnO into a harder ferrimagnet, Mn3O4. Our results indicate that the antiferromagnetic Mn enabled stronger coupling with NiFe than MnO. In addition, we find that the MnO–Mn3O4 coupling dominates the exchange bias effects at high oxygen concentrations. [ABSTRACT FROM AUTHOR]

The exchange bias effects of NiFe/Cr-oxide bilayers were studied. Results have shown that NiFe/Cr-oxide bilayers exhibited an exchange bias loop shift when field cooled to 5 K. A strong linear dependence of ferromagnetic NiFe and antiferromagnetic Cr2O3 thicknesses on the exchange bias field Hex was observed. The largest interfacial exchange energy Eint∼5.4×10-2 erg/cm2 was found in bilayers with the thickest Cr2O3 layer indicating that stronger interface exchange coupling is enabled by thicker Cr2O3 layers. In addition, Hex decreased linearly with increasing %O2/Ar ratio, reflecting that ion-beam bombardment tends to degrade the Cr2O3 surface spin structures. We also find that annealing the Cr-oxide layer yields both a structural phase transformation and improved crystallinity, giving rise to stronger exchange bias behavior. Further, the coexistence of in-plane as well as out-of-plane exchange biases was observed in a NiFe/annealed Cr2O3/Al2O3(0001) bilayer. This clearly indicates that by using the single crystal Al2O3(0001) substrate together with a rapid thermal annealing process, the antiferromagnet Cr2O3 spins are tilted toward the out-of-plane direction and thus exhibit this unusual exchange bias behavior. [ABSTRACT FROM AUTHOR]

Several analyses are conducted to explain the magnetic anisotropy dependence of the [[Pt/Co].sub.4]/NiO thin films on the thickness of the Co layer. The low temperature susceptibility of the system is shown to increase with the thickness of the Co layer.

The correlation between the ion-beam bombardment and the exchange bias magnetism in NiFe/Mn bilayers is analyzed. The dependence of the exchange bias field with increasing ion-beam energies has shown that the Ar ion-beam bombardment process has created uncompensated Mn spins or increase the spin misalignment in ferromagnet (FM)/antiferromagnet (AF) interfaces, depending on the energy used.

Mixed CoPt phases consisting of disordered fcc CoPt are responsible for the perpendicular magnetic anisotropy (PMA) for the film deposition end-Hall voltage equal to 140 V. The studies have shown that the PMA is driven by the heat of mixing and relatively higher interfacial energy since the Co layer thickness is about 1 nm.

Interfacial microstructure modulation is shown in [Ni.sub.80][Fe.sub.20]/(Ni,Fe)O thin films, where different ion bombardment energies have changed the exchange coupling between the (Ni,Fe)O and [Ni.sub.80][Fe.sub.20 interfaces. One interface configuration has provided positive or negative exchange coupling depending on whether the film is cooled with or without an external magnetic field, while another interface configuration has resulted in the more typical negative exchange coupling independent of the field cooling.

A systematic study is conducted to understand the exchange bias behavior of NiFe/Cr-oxide bilayers in terms of ferromagnet (FM) and antiferromagnet (AF) thicknesses, different percent oxygen contents, the [Al.sub.2][O.sub.3](0001) substrate, and the annealing process. The results showed that the range in exchange bias effects in NiFe/Cr-oxide bilayers is associated with different microstructures, thicknesses, and changes in AF spin orientations due to the substrate used during deposition in addition to an annealing process.

The structural and magnetic properties of NiCo/(Ni,Co)O bilayers are examined. The microstructural changes resulted from a combination of deposition oxygen content and the ion-beam bombardment has resulted in the unusual exchange bias behavior.

Results on [Ni.sub.80][Fe.sub.20]/[Co.sub.3][O.sub.4] thin film that is composed of ~ 10 nm diameter nanocrystalline columns is presented. Field cooling the films reveals low-temperature exchange-bias hysteresis loop shifts that are the same magnitude as those measured in a similar [Ni.sub.80][Fe.sub.20]/CoO system, although the bulk magnetocrystalline anisotropy is a factor of 5 smaller.

Structural and magnetic properties of the nanocomposite films of Ni80Fe20 fabricated with oxygen content in the deposition assist beam ranging from 0% to 55%are discussed. It is surmised that the ferromagnetic metallic phase of the film exists in the thin regions between the insulating antiferromagnetic nanocrystallites.

MnBi is a promising ferromagnetic material for applications at elevated temperatures due to its high Curie temperature, sizable magnetocrystalline anisotropy, and increasing coercivity with temperature. However, fabrication of MnBi thin films with ferromagnetic low-temperature phase (LTP) is conventionally difficult due to the peritectic Mn-Bi reaction and Mn oxidization. In this work, in situ Ar+-ion beam bombardment was introduced to modify the microstructure and magnetic properties of (Mn/Bi)n superlattice. Structural characterization revealed formation of MnBi LTP in the as-deposited ion-beam-bombarded samples. Vacuum annealing further promoted growth of MnBi LTP grains with c-axis orientation, leading to remarkably improved perpendicular magnetic anisotropy. Ion-beam bombardment resulted in a 200% increase in the saturation magnetization of the annealed MnBi thin film. This advancement is attributed to the enhanced interdiffusion and reaction of Mn and Bi in the ion-beam-bombarded thin films. A stability test after 150 days in air revealed a remarkable reduction in ferromagnetism due to MnBi decomposition. This work provides an effective approach for fabrication of high-quality MnBi thin films. [ABSTRACT FROM AUTHOR]

Study of efficacy of vacuum packaging techniques for chinese-style sausages is presented.

We have investigated the magnetism of NiFe/CoO/Co trilayers with different CoO spacer thicknesses. The dependence of the coercivity (Hc) and exchange bias field (Hex) on the CoO thicknesses indicated that different pinning strengths from the CoO were acting on the top NiFe and bottom Co layers, respectively. DC susceptibility indicated the different interlayer coupling energies and showed that the anisotropy of CoO layer strongly affected the temperature dependence of the magnetization. [ABSTRACT FROM AUTHOR]

Ni3Fe/(Ni,Fe)O thin films having a nanocrystallite dispersion morphology were prepared by a reactive ion beam-assisted deposition technique. The crystallite sizes of these dispersion-based films were observed to decrease from 8.4±0.3 nm to 3.4±0.3 nm as the deposition flow-rate increased from 2.78% to 7.89% O2/Ar. Thin film composition was determined using selective area electron diffraction images and Multislice simulations. Through a detailed analysis of high resolution transmission electron microscopy images, the nanocrystallites were determined to be Ni3Fe (a ferromagnet), NiO, and FeO (both antiferromagnets). It was determined that the interfacial molar Ni3Fe ratio in the nanocrystallite dispersions increased slightly at first, then decreased as the oxygen content was increased; at 7.89% O2/Ar, the interfacial molar ratio was essentially zero (only NiO and FeO remained). For nanocrystallite dispersion films grown with O2/Ar flow-rate greater than 7.89%, no interfacial (intermixed) Ni3Fe phase was detected, which resulted in no measurable exchange bias. Comparing the exchange bias field between the nanocrystallite dispersion films at 5 K, we observed a decrease in the magnitude of the exchange bias field as the nanocrystallite size decreased. The exchange bias coupling for all samples measured set in at essentially the same temperature (i.e., the exchange bias blocking temperature). Since the ferromagnetic/anti-ferromagnetic (FM/AFM) contact area in the nanocrystallite dispersion films increased as the nanocrystallite size decreased, the increase in the magnitude of the exchange bias could be attributed to larger regions of defects (vacancies and bond distortions) which occupied a significant portion of the FM/AFM interfaces in the nanocrystallite dispersion films. [ABSTRACT FROM AUTHOR]