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Full-Text Articles in Electromagnetics and Photonics
Ultra–Low Power Straintronic Nanomagnetic Computing With Saw Waves: An Experimental Study Of Saw Induced Magnetization Switching And Properties Of Magnetic Nanostructures, Vimal G. Sampath
Theses and Dissertations
A recent International Technology Roadmap for Semiconductors (ITRS) report (2.0, 2015 edition) has shown that Moore’s law is unlikely to hold beyond 2028. There is a need for alternate devices to replace CMOS based devices, if further miniaturization and high energy efficiency is desired. The goal of this dissertation is to experimentally demonstrate the feasibility of nanomagnetic memory and logic devices that can be clocked with acoustic waves in an extremely energy efficient manner. While clocking nanomagnetic logic by stressing the magnetostrictive layer of a multiferroic logic element with with an electric field applied across the piezoelectric layer is known …
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. Pettiford, A. Zeltser, S. Yoon, V. Harris, C. Vittoria, N. Sun
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. Pettiford, A. Zeltser, S. Yoon, V. Harris, C. Vittoria, N. Sun
Nian X. Sun
CoFe/PtMn/CoFe films were deposited on seed layers of Ru or NiFeCr with CoFe film compositions being either Co-10 at. %Fe or Co-16 at. %Fe. Eight periods of the CoFe/PtMn/CoFe trilayers were also prepared. The magnetic properties and ferromagnetic resonance (FMR) of these films were characterized with vibrating-sample magnetometer, and field-sweep FMR system at X band (∽9.5 GHz). The Ru-seeded CoFe/PtMn/CoFe sandwich films show excellent magnetic softness with a low hard axis coercivity of 2-4 Oe, an easy axis Mr/Ms of >98%, and a significantly enhanced in-plane anisotropy of 57-123 Oe when CoFe layer thickness is above 200 …
Measurements And Simulations Of Micron Size Coplanar Waveguides, S. Zhang, J. B. Sokoloff, C. Vittoria
Measurements And Simulations Of Micron Size Coplanar Waveguides, S. Zhang, J. B. Sokoloff, C. Vittoria
Jeffrey Sokoloff
Measurements and simulations have been done on a coplanar waveguide, which consists of a pair of slots which taper down to a separation and width of micron size. The purpose of this device is to permit one to concentrate microwaves or millimeter waves on magnetic samples of the order of a micron in order to do ferrimagnetic resonance (FMR) studies on such small samples. The transmission coefficient as a function of frequency found in the simulations agrees quite well with the measurements. The simulations show that the magnetic field at the pinch is about a factor of several thousand larger …
Intrinsic Ferromagnetic Resonance Linewidth Of Barium Ferrite Due To Spin-Wave Scattering By Trigonal Site Single-Particle Excitations, J. Sokoloff, S. Marshall, C. Vittoria
Intrinsic Ferromagnetic Resonance Linewidth Of Barium Ferrite Due To Spin-Wave Scattering By Trigonal Site Single-Particle Excitations, J. Sokoloff, S. Marshall, C. Vittoria
Jeffrey Sokoloff
Time-dependent two-magnon scattering was previously proposed as a mechanism to explain the large magnitude of the ferrimagnetic resonance (FMR) linewidth of barium ferrite as a function of frequency. In the present work, it is shown that a quantum mechanical mechanism like the Kasuya-Le Craw process (KL) but with the phonon excitation replaced by a single-particle excitation of a trigonal site iron ion, which moves in an anharmonic potential well, gives a linewidth contribution of less than a tenth of an Oersted and proportional to the frequency, as in the KL mechanism. We conclude, based on this work and our previous …
Electrostatic Tuning Of Ferromagnetic Resonance And Magnetoelectric Interactions In Ferrite-Piezoelectric Heterostructures Grown By Chemical Vapor Deposition, Ning Li, Ming Liu, Ziyao Zhou, Nian X. Sun, D. V. B. Murthy, Gopalan Srinivasan, Tonya M. Klein, Vladimir M. Petrov, Arunava Gupta
Electrostatic Tuning Of Ferromagnetic Resonance And Magnetoelectric Interactions In Ferrite-Piezoelectric Heterostructures Grown By Chemical Vapor Deposition, Ning Li, Ming Liu, Ziyao Zhou, Nian X. Sun, D. V. B. Murthy, Gopalan Srinivasan, Tonya M. Klein, Vladimir M. Petrov, Arunava Gupta
Nian X. Sun
Magnetoelectric interactions as a function of applied electric field have been studied in ferrite-ferroelectric heterostructures at microwave frequencies. The measurements are performed on 1.5–2.0 μm thick nickel ferrite (NiFe₂O₄) films grown heteroepitaxially on lead zinc niobate-lead titanate and lead magnesium niobate-lead titanate substrates using direct liquid injection chemical vapor deposition. Large shifts in the ferromagnetic resonance profile are observed in these heterostructures due to strong magnetoelectric coupling resulting from electrostatic field induced changes in the magnetic anisotropy field. Theoretical estimates of field shifts are in good agreement with the experimental data.
Ferromagnetic Resonance Of Micrometer-Sized Samples, S. Zhang, S. A. Oliver, N. E. Israeloff, A. Widom, C. Vittoria
Ferromagnetic Resonance Of Micrometer-Sized Samples, S. Zhang, S. A. Oliver, N. E. Israeloff, A. Widom, C. Vittoria
Nathan Israeloff
Submicrometer-sized slotline and coplanar waveguide devices were used for ferromagnetic resonance (FMR) measurement on submicrometer-sized magnetic fine particles. FMR measurements were taken on individual magnetic disks, having diameters ranging from 50 to 1 μm, using either a slotline-coplanar waveguide (CPW) junction device or a coplanar waveguide transmission line junction device. The magnetic samples were etched from a 105 nm thick amorphous Fe₈₀B₁₅Si₅ film on a quartz substrate. Absorption modes, which were measured with the submicrometer-sized slotline CPW, followed the Kittel magnetic resonance model for frequencies from 1 to 20 GHz for the 1 μm diam disk. By detecting the second …
Ferromagnetic Resonance Measurements On Epitaxial Grown Fe/Znse And Co/Znse Films On Gaas Substrates, S. A. Oliver, C. Vittoria, J. J. Krebs, B. T. Jonker, G. A. Prinz
Ferromagnetic Resonance Measurements On Epitaxial Grown Fe/Znse And Co/Znse Films On Gaas Substrates, S. A. Oliver, C. Vittoria, J. J. Krebs, B. T. Jonker, G. A. Prinz
Carmine Vittoria
Ferromagnetic resonance (FMR) measurements have been performed over a broad frequency range on epitaxial films of Co and bcc α‐Fe grown onto epilayers of ZnSe by molecular‐beam‐epitaxy techniques on (001) and (110) GaAs substrates. In‐plane and perpendicular FMR results were used in deducing the magnetic parameters and spin‐wave resonance (SWR) dispersion of the films. The magnetic parameters deduced for Fe films agree with previous results obtained on the (001) Fe/ZnSe film. Well‐resolved SWR modes were observed in the Fe/ZnSe films, allowing extraction of the exchange stiffness constant. Few spin‐wave excitations were observed for the Co/ZnSe films. Both (110) Fe/ZnSe and …
Nonreciprocal Coupling Structure Of Dielectric Wave-Guides, P. Kwan, C. Vittoria, J. Proske
Nonreciprocal Coupling Structure Of Dielectric Wave-Guides, P. Kwan, C. Vittoria, J. Proske
Carmine Vittoria
M-type hexagonal ferrites have been incorporated in a coupled dielectric image guides structure for nonreciprocal microwave circuits design. Two different field configurations have been considered in this paper: for case I the c axis of the ferrite materials was aligned along the direction of propagation; for case II the c axis was aligned in the transverse direction. Electromagnetic wave scattering S parameters of the device were measured for an external biasing magnetic field applied parallel and perpendicular to the c axis of the ferrite slab. We have observed nonreciprocal microwave effects in the ferromagnetic resonance regime as a result of …
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Vincent G. Harris
The evolution of magnetic properties and local atomic ordering during thermal annealing has been studied for amorphous Fe₇₅Ni5B₁₅Si₅ thin films. Resistivity, vibrating sample magnetometer (VSM), ferromagnetic resonance (FMR), extended x-ray absorption fine structure (EXAFS), and Mossbauer effect (ME) measurements were taken on samples annealed at various temperatures ranging to film crystallization. The as-deposited samples are in a close-packed structure with little short-range order. Samples annealed above 200°C show ordering of the boron shell, but no indication of long-range ordering. With the exception of the anisotropy and coercive fields, no change in the magnetic or microwave magnetic parameters is observed for …
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Vincent G. Harris
CoFe/PtMn/CoFe films were deposited on seed layers of Ru or NiFeCr with CoFe film compositions being either Co-10 at. %Fe or Co-16 at. %Fe. Eight periods of the CoFe/PtMn/CoFe trilayers were also prepared. The magnetic properties and ferromagnetic resonance (FMR) of these films were characterized with vibrating-sample magnetometer, and field-sweep FMR system at X band (∽9.5 GHz). The Ru-seeded CoFe/PtMn/CoFe sandwich films show excellent magnetic softness with a low hard axis coercivity of 2-4 Oe, an easy axis Mr/Ms of >98%, and a significantly enhanced in-plane anisotropy of 57-123 Oe when CoFe layer thickness is above 200 Å. Contrary to …
Magnetic And Microwave Magnetic Properties Of Barium Hexaferrite Permanent Magnet Films Having The C-Axis In The Film Plane, S. D. Yoon, C. Vittoria, S. A. Oliver
Magnetic And Microwave Magnetic Properties Of Barium Hexaferrite Permanent Magnet Films Having The C-Axis In The Film Plane, S. D. Yoon, C. Vittoria, S. A. Oliver
Carmine Vittoria
Thick (1-14 μm) films of ferrimagnetic barium hexaferrite (BaFe₁₂O₁₉ or BaM) having the c-axis ([0001]) in the film plane were deposited by pulsed laser deposition onto a-plane (1120) sapphire (Al₂O₃) substrates, and were found to have a (1010) orientation. Torque and magnetization measurements show these films are permanent magnets with easy magnetization direction in the plane of the film. Ferrimagnetic resonance (FMR) spectra exhibited linewidths of 1.00-1.40 kOe, where low-field FMR measurements do not show uniform mode broadening due to the formation of multiple domains. All film parameters were affected by the large stress present in these films due to …
Ferromagnetic-Resonance In Magnetic Multilayer Structures, S. W. Mcknight, C. Vittoria
Ferromagnetic-Resonance In Magnetic Multilayer Structures, S. W. Mcknight, C. Vittoria
Carmine Vittoria
We have calculated the FMR line shape for magnetic multilayer structures of alternating iron and iron-alloy layers. The model assumes abrupt interfaces and that spins on adjacent layers are ferromagnetically coupled with an exchange constant A₁₂. The surface magnetic anisotropy fields are set to zero in our calculations. As A₁₂ is increased, satellite lines in the surface impedance split off from the ferromagnetic resonance main lines of the component materials. The number of satellites is one more than the number of layered pairs. The position and strength of these lines is found to be dependent on the relative layer thicknesses …
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Vincent G. Harris
The interest in barium hexaferrite thick films, particularly with high remanent magnetization, is driven by the development of small planar ferrite microwave devices. We report here processing and microwave characterization of BaFe₁₂O₁₉ ferrite thick films (100-400 μm). The films were deposited on silicon and alumina substrates by screen printing, oriented under a magnetic field of 8 kOe, then annealed at 250°C and sintered at temperatures ranging from 850 to 1300°C. Scanning electron microscopy and x-ray diffraction exhibited strong crystallographic alignment of c-axis crystals perpendicular to the film plane. The magnetization measurement indicated that a typical dense film with 270 μm …
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Magnetic And Microwave Properties Of Cofe/Ptmn/Cofe Multilayer Films, C. I. Pettiford, A. Zeltser, S. D. Yoon, V. G. Harris, C. Vittoria, N. X. Sun
Carmine Vittoria
CoFe/PtMn/CoFe films were deposited on seed layers of Ru or NiFeCr with CoFe film compositions being either Co-10 at. %Fe or Co-16 at. %Fe. Eight periods of the CoFe/PtMn/CoFe trilayers were also prepared. The magnetic properties and ferromagnetic resonance (FMR) of these films were characterized with vibrating-sample magnetometer, and field-sweep FMR system at X band (∽9.5 GHz). The Ru-seeded CoFe/PtMn/CoFe sandwich films show excellent magnetic softness with a low hard axis coercivity of 2-4 Oe, an easy axis Mr/Ms of >98%, and a significantly enhanced in-plane anisotropy of 57-123 Oe when CoFe layer thickness is above 200 Å. Contrary to …
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Vincent G. Harris
We report on a new technique for the determination of the linear magnetostriction constant of thin films. The technique uses the shift in ferromagnetic resonance (FMR) of a magnetostrcitive sample upon application of an external stress. A circular thin film is deposited onto a fused quartz place by ion beam sputter deposition. The place is mounted in a cantilever configuration, with the film suspended over the junction of a slot-line/coplanar guided structure. The slot line proved a rf magnetic field normal to the film place, tunable over the frequency range 0.1 GHz
Out-Of-Plane Ferromagnetic-Resonance Study Of Magnetically Coupled Fe/Cr/Fe Films, S. A. Oliver, C. Vittoria, J. J. Krebs, P. Lubitz, G. A. Prinz
Out-Of-Plane Ferromagnetic-Resonance Study Of Magnetically Coupled Fe/Cr/Fe Films, S. A. Oliver, C. Vittoria, J. J. Krebs, P. Lubitz, G. A. Prinz
Carmine Vittoria
Magnetically coupled single-crystal Fe/Cr/Fe (001) sandwiches have been studied by the ferromagnetic resonance (FMR) techniques. Such films have been previously shown to be antiferromagnetically coupled for a chromium layer thickness range 12 Å< tcr < 25 Å by variable frequency ferromagnetic resonance measurements along principal crystallographic axes, and other techniques. These measurements have been extended to include oblique angle application of the applied magnetic field (H) between principal crystallographic axes in the film plane and the film normal. Measured films had tcr = 13, 16, 17, and 28 Å. Ferromagnetic resonance measurements were taken using a fixed frequency 9.5-GHz cavity. Resonances …
Dyadic Green's Function Calculations On A Layered Dielectric/Ferrite Structure, H. How, X. Zuo, C. Vittoria
Dyadic Green's Function Calculations On A Layered Dielectric/Ferrite Structure, H. How, X. Zuo, C. Vittoria
Carmine Vittoria
Dyadic Green's function techniques have been applied to solve the transmission properties of a microstrip line fabricated on top of a single-crystal Y-type hexaferrite substrate. Current potentials are used to construct the Galerkin elements to facilitate solution accuracy even in the FMR region. Transmission coefficients of a microstrip line fabricated on a Y-type hexaferrite substrate were thus calculated, which compared reasonably well with measurements.
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Magnetostriction Measurements On Thin-Films By A Slot-Line Ferromagnetic-Resonance Technique, S. A. Oliver, V. G. Harris, C. Vittoria
Carmine Vittoria
We report on a new technique for the determination of the linear magnetostriction constant of thin films. The technique uses the shift in ferromagnetic resonance (FMR) of a magnetostrcitive sample upon application of an external stress. A circular thin film is deposited onto a fused quartz place by ion beam sputter deposition. The place is mounted in a cantilever configuration, with the film suspended over the junction of a slot-line/coplanar guided structure. The slot line proved a rf magnetic field normal to the film place, tunable over the frequency range 0.1 GHz
Intrinsic Ferromagnetic Resonance Linewidth Of Barium Ferrite Due To Spin-Wave Scattering By Trigonal Site Single-Particle Excitations, J. B. Sokoloff, S. P. Marshall, C. Vittoria
Intrinsic Ferromagnetic Resonance Linewidth Of Barium Ferrite Due To Spin-Wave Scattering By Trigonal Site Single-Particle Excitations, J. B. Sokoloff, S. P. Marshall, C. Vittoria
Carmine Vittoria
Time-dependent two-magnon scattering was previously proposed as a mechanism to explain the large magnitude of the ferrimagnetic resonance (FMR) linewidth of barium ferrite as a function of frequency. In the present work, it is shown that a quantum mechanical mechanism like the Kasuya-Le Craw process (KL) but with the phonon excitation replaced by a single-particle excitation of a trigonal site iron ion, which moves in an anharmonic potential well, gives a linewidth contribution of less than a tenth of an Oersted and proportional to the frequency, as in the KL mechanism. We conclude, based on this work and our previous …
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Magnetic-Properties And Local Ordering During Thermal Annealing Of Amorphous Fe₇₅Ni5b₁₅Si₅ Films, S. A. Oliver, V. G. Harris, C. Vittoria, W. T. Elam, K. H. Kim, H. H. Hamdeh, M. Alhabash
Carmine Vittoria
The evolution of magnetic properties and local atomic ordering during thermal annealing has been studied for amorphous Fe₇₅Ni5B₁₅Si₅ thin films. Resistivity, vibrating sample magnetometer (VSM), ferromagnetic resonance (FMR), extended x-ray absorption fine structure (EXAFS), and Mossbauer effect (ME) measurements were taken on samples annealed at various temperatures ranging to film crystallization. The as-deposited samples are in a close-packed structure with little short-range order. Samples annealed above 200°C show ordering of the boron shell, but no indication of long-range ordering. With the exception of the anisotropy and coercive fields, no change in the magnetic or microwave magnetic parameters is observed for …
Zero Magnetic-Field Ferromagnetic-Resonance Properties Of Single-Crystal Yig/Ggg/Yig Layers, K. Sun, P. Dorsey, C. Vittoria
Zero Magnetic-Field Ferromagnetic-Resonance Properties Of Single-Crystal Yig/Ggg/Yig Layers, K. Sun, P. Dorsey, C. Vittoria
Carmine Vittoria
This study is an extension of previous work dealing with single crystals of YIG/GGG/YIG grown in (110) layers. Ferromagnetic resonance (FMR) measurements for fields along the axis were performed. The microwave measurements reveal hysteretic behavior as the FMR frequency is measured for positive and negative magnetic fields H. For H in which the magnetic moment is zero (spin flop) the FMR frequency goes through a discrete and measurable jump or change. This discontinuity in the FMR frequency at the spin-flop condition is attributed to the magnetostatic interaction between the two YIG layers.
Measurements And Simulations Of Micron Size Coplanar Waveguides, S. Zhang, J. B. Sokoloff, C. Vittoria
Measurements And Simulations Of Micron Size Coplanar Waveguides, S. Zhang, J. B. Sokoloff, C. Vittoria
Carmine Vittoria
Measurements and simulations have been done on a coplanar waveguide, which consists of a pair of slots which taper down to a separation and width of micron size. The purpose of this device is to permit one to concentrate microwaves or millimeter waves on magnetic samples of the order of a micron in order to do ferrimagnetic resonance (FMR) studies on such small samples. The transmission coefficient as a function of frequency found in the simulations agrees quite well with the measurements. The simulations show that the magnetic field at the pinch is about a factor of several thousand larger …
Microwave And Magnetic Properties Of Barium Hexaferrite Films Having The C-Axis In The Film Plane By Liquid Phase Epitaxy Technique, S. D. Yoon, C. Vittoria
Microwave And Magnetic Properties Of Barium Hexaferrite Films Having The C-Axis In The Film Plane By Liquid Phase Epitaxy Technique, S. D. Yoon, C. Vittoria
Carmine Vittoria
We report the growth of thick barium hexaferrite (BaFe₁₂O₁₉,BaM) films on m-planes ([1100] or [1010]) sapphire (Al₂O₃) substrates by the liquid phase epitaxy deposition technique. The procedure entailed the deposition of seed layers of BaFe₁₂O₁₉ onto the substrate by the pulsed laser ablation deposition and then dipping the substrate into a molten flux for 2 h. The total thickness ranged from 60 μm to 200 μm. The vibrating sample magnetometer (VSM) measurement data showed that the film exhibited magnetic uniaxial anisotropy axis in the film plane. The coercive field was relatively small, range of Hc was from 0.007 kOe to …
Ferromagnetic-Resonance Of Exchange-Coupled Magnetic Layers, C. Vittoria
Ferromagnetic-Resonance Of Exchange-Coupled Magnetic Layers, C. Vittoria
Carmine Vittoria
The ferromagnetic resonance-line shapes, fields, and intensities of exchange coupled magnetic multilayers are calculated as a function of exchange coupling and number of layers. We find that the number of magnetic excitations equals the number of layer pairs that make up the layered structure. The magnetic dispersion of these excitations is easily calculable from the theoretical formulation developed earlier. It is suggested that the multitude of ferromagnetic resonance lines in magnetic superlattices observed experimentally elsewhere may be explained in terms of an earlier calculation involving surface magnetic anisotropy fields only.
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Microwave And Magnetic Properties Of Self-Biased Barium Hexaferrite Screen Printed Thick Films, Y. J. Chen, A. L. Geiler, T. Sakai, S. D. Yoon, C. Vittoria, V. G. Harris
Carmine Vittoria
The interest in barium hexaferrite thick films, particularly with high remanent magnetization, is driven by the development of small planar ferrite microwave devices. We report here processing and microwave characterization of BaFe₁₂O₁₉ ferrite thick films (100-400 μm). The films were deposited on silicon and alumina substrates by screen printing, oriented under a magnetic field of 8 kOe, then annealed at 250°C and sintered at temperatures ranging from 850 to 1300°C. Scanning electron microscopy and x-ray diffraction exhibited strong crystallographic alignment of c-axis crystals perpendicular to the film plane. The magnetization measurement indicated that a typical dense film with 270 μm …
Spin-Wave Resonance In Fenibsi Films, J. Xia, J. S. Ryu, C. Vittoria
Spin-Wave Resonance In Fenibsi Films, J. Xia, J. S. Ryu, C. Vittoria
Carmine Vittoria
Ferromagnetic resonance (FMR) measurements have been performed on thin films of Fe₈₀-xNixB₁₅Si₅ alloys (x = 5, 40, and 60). The effective magnetization (4πMeff), magnetic anisotropy field (HA), and g factor were measured. The values of g for all the films ranged between 1.90 < 2.11. Spin-wave resonance (SWR) excitations were observed for H, the magnetic field, applied perpendicular to the film plane. SWR fields were found to obey the n² law and yielded exchange constants in the range of A = O.2-L9x 10-6 ergs/cm. The nearest neighbor exchange parameter J was deduced from A and implies that J varies within a …