Meetings & Events

Spring 1999 logo1999 MRS Spring Meeting & Exhibit

April 5-9, 1999 | San Francisco
Meeting Chairs: Katayun Barmak, James S. Speck, Raymond T. Tung, Paul D. Calvert



Symposium L—Polycrystalline Metal and Magnetic Thin Films

Chairs

David Laughlin 
Dept of MS&E 
Carnegie Mellon Univ 
Wean Hall 3307 
Pittsburgh, PA 15213-3890 
412-268-2706

Kenneth Rodbell 
Silicon Technology 
IBM T.J. Watson Research Lab 
Room 05-221 
Yorktown Heights, NY 10598 
914-945-1012

Olivier Thomas 
MATOP CNRS 
Univ of Aix Marseille III 
Marseille, 13013 FRANCE 
33-049-128-8672

Bing Zhang
Sputter Technology Lab
MaxMedia
San Jose, CA 95131 
408-232-8697

Symposium Support 
*IBM T.J. Watson Research Center 
*MMC Technology (MaxMedia)

Proceedings published as Volume 562 
of the Materials Research Society 
Symposium Proceedings Series.

* Invited paper
SESSION L1: MAGNETIC THIN FILMS 
Chair: Bing Zhang 
Monday Afternoon, April 5, 1999 
Salon 4 (M)
1:30 PM *L1.1 
MICROSTRUCTURAL CHARACTERIZATION OF CoCr(PtTa) LONGITUDINAL MAGNETIC RECORDING MEDIA. James E. Wittig , Vanderbilt University, Nashville, TN; James Bentley, Oak Ridge National Laboratory, Oak Ridge, TN and Thomas P. Nolan, Komag Inc., San Jose, CA.

Development of high-density longitudinal recording media with good noise performance and high thermal stability requires optimization of both alloy composition and processing methods. In CoCr(PtTa) thin films, grain boundary Cr segregation provides the mechanism for magnetic decoupling of individual grains. The corresponding Cr depletion within the Co grains also changes the ``bulk'' magnetic anisotropy (Ku). Therefore, modeling of the magnetic properties requires an accurate quantitative description of the Cr distribution. An invaluable tool for this analysis is energy filtered transmission electron microscopy (EFTEM). Experimental methods have been refined to use EFTEM images for quantitative elemental maps of the Cr distribution with spatial resolution on the order of  1 nm. Since a single Cr map may contain more than one hundred Co grains, a statistical description of the Cr distribution is directly available. In addition, EFTEM is an ideal method for grain size measurements. EFTEM reveals only the grains with sufficient grain boundary Cr segregation to be considered as isolated magnetic units. Combining EFTEM with other characterization methods, such as high resolution transmission electron microscopy (HRTEM), electron diffraction, and nanoprobe energy dispersive spectroscopy (EDS), provides a complete picture of the media microstructure. These methods have been used to characterize a series of CoCrPt/Cr, CoCrTa/Cr, and CoCrPtTa/Cr longitudinal media, sputtered with various processing conditions, in order to understand their structure-property-processing relationships. Research at the ORNL SHaRE User Facility was supported by the Division of Materials Sciences, U.S. Department of Energy under contract DE-AC05-96OR22464 with Lockheed Martin Energy Research Corp., and through the SHaRE Program under contract DE-AC05-76OR00033 with Oak Ridge Associated Universities.

2:00 PM L1.2 
INTERFACE GOVERNED MAGNETOSTRICTION IN ULTRA THIN Co50Fe50 AND Co FILMS. Roland Mattheis , Juergen Langer, Gisela Quednau, Institut f. Pysikalische Hochtechnologie, Jena, GERMANY; Stephan Senz, Max-Planck-Institut f. Mikrostrukturphysik, Weinberg, Halle, GERMANY; Juergen Kraeusslich, IOQ Friedrich-Schiller-Universitaet, Max-Wien-Platz, Jena, GERMANY.

Magnetic devices used for spin electronics like GMR sensors or magnetic tunnelling junctions for MRAM require multilayer stacks containing magnetic thin films with individual thicknesses down to one nm. In the thickness range of 1 to 10 nm interface- related properties can govern the behaviour and large deviation from bulk may occur. For sensors and MRAM application, the coercivity and magnetostriction should be as low as possible at least for the soft sensing layer. To study these magnetic properties of magnetic films down to one nm thickness a new method for determination of the anisotropy field strength Hk was developed. This method uses the longitudinal Kerr effect to determine the magnetisation vector of a saturated specimen in a rotating field. By proper adjustment of the magnetooptical system, a simple and exact correction of the second order magnetooptical effect known as Couton-Mutton-effect could be performed for the first time. This correction allows the direct and very exact determination of the Hk. The magnetostriction was determined by studying the variation of Hk at different applied strains. These studies were performed on sputtered Co and Co50Fe50(X) films sandwiched in a Ta/Cu/X/Cu/Ta system. For the strong magnetostrictive CoFe film a remarkable thickness dependence was found. Due to the negative sign of the interface contribution a magnetostriction free film was obtained at a thickness around 1 nm. The polycrystalline fcc Co films display a low and nearly constant magnetostriction down to 3 nm. For thinner films, additional contributions increase the value of the magnetostriction significantly. The magnetic behaviour will be discussed in relation to the film and interface structure determined by TEM and X-Ray reflectometry.

2:15 PM L1.3 
MAGNETIC ANISOTROPY IN ELECTRODEPOSITED Co FILMS AND SPIN-VALVES ON GaAs SUBSTRATES. Karen Attenborough , Magali Cerisier, Katholieke Univ Leuven, Dept of MTM, Leuven, BELGIUM; Hans Boeve, Jo De Boeck, Gustaaf Borghs, IMEC, Dept MAP/NMC, Leuven, BELGIUM; Jean-Pierre Celis, Katholieke Univ Leuven, Dept of MTM, Leuven, BELGIUM.

Recently, we reported the first soft switching Co/Cu spin-valve structures grown by electrodeposition. The device consisted of a symmetric stack of Co free layers decoupled by Cu spacer layers around a central harder substructure, deposited directly on n-GaAs. High magnetoresistance values of up to 6% with high sensitivities of up to 0.7%/Oe were achieved. These results have significant implications for the production of low cost magnetic field sensors. We choose to electrodeposit the structure directly onto GaAs to avoid the need of a buffer layer which would strongly reduce the performance of the device due to current shunting. It was also seen that the Co/GaAs interface induces an in-plane anisotropy in the films which is responsible for these remarkable spin-valve properties. In order to be able to tailor the properties of these spin-valves, the cause and influence of this anisotropy is studied and presented here. Atomic force microscopy (AFM) studies are performed on single layers of varying nanometer thicknesses, deposited directly onto a semiconductor and for comparison onto an electrodeposited Cu buffer layer. The development of the texture and the grain size distribution from the initial layer to the full structure is reflected in the magnetic properties of the structure and shows that there are different competing contributions of the interfacial anisotropy and magnetic coupling phenomena within the structure. This particular spin-valve structure shows strong potential for application at higher temperatures. Therefore, annealing experiments were performed to study the influence of strain, texture and interfacial interdiffusion on the single layers and on the magnetoresistance properties of the full structure.

2:30 PM L1.4 
HIGHLY ORIENTED Co ALLOY SOFT MAGNETIC FILMS ON Si SUBSTRATES. Heng Gong , Wei Yang, Maithri Rao, David E. Laughlin and David N. Lambeth, Carnegie Mellon University, Data Storage Systems Center, Pittsburgh, PA.

Soft magnetic thin films are widely used in magnetic storage applications and the control of the crystalline orientation and microstructure is desirable as this directly influences the anisotropy, coercivity and device functionality. Recently, very thin films of soft Co and Co based alloys have become important for sensor applications. In particular, Co and Co90Fe10 alloys are currently used in GMR spin valve structures for ultra-high density magnetic recording. Hence, it is of considerable interest to fully understand the properties of soft Co films. Previously we have discussed, highly oriented, NiFe (permalloy) films epitaxially grown on Ag and Cu underlayer templates, which were grown on HF etched Si substrates by sputter deposition. In this study, using similar template techniques, highly oriented Co and Co based alloy thin films with soft magnetic properties have been successfully prepared on HF etched Si(111) substrates. From TEM and X-ray pole figure phi scan measurements, it was found that fcc phase Co grows on Ag underlayers and the epitaxial relationship was determined to be Co (111) [11-2]  Ag (111) [11-2]  Si (111) [11-2]. It was also observed that both the Co and Ag layers contain two twin-related orientations of grains. Since the lattice match between Cu and Co is much better than that of Ag and Co, samples with Cu buffer layers between the Ag and Co films were also prepared. Epitaxial growth of Co(111)  Cu(111)  Ag(111)  Si(111) was confirmed for samples sputtered at room temperature. This structure appears to alleviate the interfacial stress, especially when the required Co film thickness is very small. However, film growth at elevated temperatures, 260 C, on the Cu template can induce the hard Co hcp phase instead of the soft fcc phase. The magnetic and microstructual properties of these film systems will be presented.

3:15 PM *L1.5 
STRUCTURE AND SENSOR PROPERTIES OF A ROBUST GMR MATERIAL SYSTEM. K.M.H. Lenssen , Philips Research Laboratories, Eindhoven, THE NETHERLANDS; J.J.T.M. Donkers, Philips Centre for Manufacturing Technology, Eindhoven, THE NETHERLANDS; A.E.T. Kuiper, Philips Research Laboratories, Eindhoven, THE NETHERLANDS; J. Van Driel, Van der Waals-Zeeman Institute, Univ. of Amsterdam, THE NETHERLANDS.

Already in the first decade after its discovery the Giant Magnetoresistance (GMR) effect has attracted much attention, mainly because of the possibility for application in recording heads. Recently we have developed a GMR material system that is so robust that it can even fulfil the strong requirements for sensors in automotive applications. This GMR multilayer comprises an exchange-biased Artificial Antiferromagnet (AAF). To obtain the favourable sensor properties the choice of the materials and their structure is very important. In order to achieve an excellent thermal stability IrMn has been used as the exchange-biasing material, while interface diffusion is suppressed by avoiding interfaces between easily mixing materials. Magnetic robustness is obtained by using an AAF, consisting of CoFe/Ru/CoFe, as the pinned layer. Thus the field range over which the magnetizations of the pinned and the free layer are not parallel is increased by more than a factor of 5. The major disadvantage of conventional AAF's, i.e. irreversible flipping in higher magnetic fields, has been eliminated by the exchange biasing, as has been demonstrated for fields >150 kA/m. For information about the material structure we have performed extensive TEM-analyses, in particular to study the texture. For example, a high degree of (111) texture is generally advantageous for the exchange-biasing effect. In this presentation the influence of the material structure on the magnetic and electric properties will be illustrated by examples from the development of our robust GMR multilayer.

3:45 PM L1.6 
SPIN-VALVE GMR FILMS BASED ON ANTIFERROMAGNETIC NiMn. Geoff W. Anderson , Yiming Huai, Lena Miloslavsky, Spin-Valve Materials Process, Read-Rite Corporation, Fremont, CA.

The antiferromagnetic alloy NiMn has demonstrated a high exchange coupling field (Hex) to a coupled NiFe film and high corrosion resistance after annealing at 255C. This is promising for the pinning layer of a spin-valve film and the domain control biasing layer of a sensing layer [1]. In this work we have investigated the magnetic and structural properties of spin-valve films exchange biased by CoFe/NiMn compared to CoFe/IrMn spin valves. A spin-valve film of structure Ta50A/NiFe50A/CoFe20A/Cu28A/CoFe22A/ NiMn300A/Ta50 showed a giant-magnetoresistance of 5.5% with a Hex 850 Oe after annealing. The blocking temperature (Tb) of this film is about 400C, compared to 250C for IrMn80A based spin-valve films. The remnant blocking temperature was also measured by soaking the sample at an elevated temperature for 5 minutes and cooling down to RT in an applied field of 300 Oe opposing the pining field. It was found that for NiMn spin-valves Hex was almost constant up to a temperature of 375C, in contrast to 180C for an IrMn spin-valve. A further indication of the superior thermal stability of NiMn spin-valves is that at 150C a 3.7% magnetoresistance remains (a decrease of 33% due to heating), significantly better that the 50% degradation observed in IrMn based spin-valves under identical conditions. Structural ordering of the NiMn in an fct phase after annealing has been observed using x-ray diffraction, with the data exhibiting pure fcc(fct)(111) texture. It was found that the fct peak position shifted to a higher diffraction angle with increased annealing temperature from 250C to 270C. [1] T. Lin, D. Mauri, N. Staud, C. Hwang, K. Howard and G. Gorman, Appl. Phys. Lett., Vol 65, No. 9, 1163 (1994).

4:00 PM L1.7 
MAGNETORESISTANCE OF THIN FILMS OF La1-xMxOy GROWN BY LD-MOCVD ON Si(100). Nelly Mateeva , Phillip Hogan, Klaus-Hermann Dahmen, Department of Chemistry and MARTECH, Florida State University, Tallahassee, FL.

Thin films of La1-xMxOy(where M is Ca2+, Sr2+, Ba2+ or Pb2+) have been deposited by LD-MOCVD on Si(100) substrate as well as on yttrium stabilized zirconium oxide (YSZ) as a buffer layer over Si(100). X-ray diffraction studies have shown, that the films are polycrystalline. If La3+ is partially substituted by alkali earth metal ions, the films grow preferentially in 100 direction. In case of Pb2+ both 100 and 200 orientations are present. Yttrium stabilized zirconium oxide forms thin polycrystalline layers on Si(100) with preferred 110 orientation.Using YSZ as a buffer layer does not change the orientation of La1-xMxOy film. The composition of the films were determined by Energy Dispersive Spectroscopy (EDS). 
Resistance measurements were performed on this films in a magnetic field of 0 and 5 T respectively. Magnetoresistance effect has been observed and discussed in terms of film composition, morphology and growing conditions. The effect of post-annealing of the films in oxygen atmosphere on the crystallinity and magnetic properties has also been discussed.

4:15 PM L1.8 
MAGNETIC ANISOTROPY IN La0.7(Sr,Ca)0.3MnO3 EPITAXIAL THIN FILMS AND CRYSTALS. K. Steenbeck , R. Hiergeist, W. Andrá, Institut fur Physikalische Hochtechnologie e.V. Jena, GERMANY; A. Revcolevschi, L. Pinsard-Gaudart, Laboratoire Chimie des Solides, Universite Paris, FRANCE.

Ferromagnetic La0.7Sr0.3MnO3 (LSMO) thin films have been sputtered on different single crystal substrates (SrTiO3, LaAlO3, Si/YSZ, MgO). Their in plane magnetic anisotropy was measured by the torque method in the temperature range from 20 K up to room temperature. Furthermore, the anisotropy of a bulk LSMO single crystal was measured and compared with that of the films. Describing LSMO as a pseudocubic lattice with the <100> directions connecting two La atoms at the distance of about 0.39 nm we find the dominating anisotropy to be biaxial with easy axes <110> for (100) oriented films on all (100) substrates. The anisotropy can be described by the cubic crystal anisotropy constant K1, which changes from zero at the Curie Temperature to about -105 erg/cm3 at low temperatures. A small uniaxial anisotropy up to 103 erg/cm3 is superimposed, which can be interpreted as stress induced anisotropy with an at random oriented easy axis. Similar results are found for La0.7Ca0.3MnO3 films. K1 of the bulk crystal was smaller than in films, but also negative.

SESSION L2: TEXTURED AND MULTILAYERED THIN FILMS 
Chair: David E. Laughlin 
Tuesday Morning, April 6, 1999 
Salon 4 (M)
8:30 AM *L2.1 
ELECTRON DIFFRACTION INVESTIGATION OF CRYSTALLOGRAPHIC TEXTURE OF THIN FILMS. Li Tang , Shanlin Duan, IBM, Storage System Division, San Jose, CA; David E. Laughlin, Dept of Materials Science and Engineering and Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, PA.

A method of invetigating thin film crystallographic texture by electron diffraction is reviewd. The reciprocal lattices of fibrous and lamellar textured thin films are spherical belts around the texture axis. A general equation, which describes the projection of the spherical belts onto Ewald sphere along the incident electron beam direction, has been derived. Based on this eaquation the geometric and intensity evolution of the electron diffraction patterns with the tilt angle about an arbitrary axis in the film plane could be analyzed in a systematic way. The geometric characteristics of the electron diffraction patterns could then be used to derive the texture axis directional index and its angular distribution. In combination with the dark field imaging techniques in transmission electron microscopy the knowledge of the intensity of the diffraction patterns could be used to obtain the fraction of grains in the films having a certain type of texture. This method has been applied to both single layered and multilayered thin films of various applications. Examples of the technique applied to thin films for magnetic recording will be presented.

9:00 AM L2.2 
THE INFLUENCE OF PATTERNING IN Co AND Co/Pd MULTILAYER STRUCTURES. C.N. Borca , Rui-hua Cheng and P.A. Dowben, University of Nebraska at Lincoln, Department of Physics and Astronomy, Lincoln, NE.

Different methods can be adopted to fabricate patterned thin films with features spatially restricted in micron-scale regime. We are studying ferromagnetic films of cobalt and cobalt - palladium heterostructures fabricated by laser assisted chemical deposition from organometalic compounds. We have developed this one-step deposition technique sufficiently to deposit pure metal features with excellent spatial resolution and in multilayer geometries. From the comparison between the continuous and patterned films we can conclude that the patterning of the films into arrays of discrete micron-scale features has a greater influence on the magnetic properties of the films than changes microstructure and film growth. We characterize the magnetic structures using LEED, MFM, X-ray and MOKE.

9:15 AM L2.3 
ELECTROCRYSTALLIZATION AND TEXTURE OF NICKEL ELECTRODEPOSITS. Yang Cao , J.A. Szpunar, Department of Metallurgical Engineering, McGill University, Montreal, PQ, CANADA.

The microstructure and texture of nickel coatings which are electrodeposited were investigated by X-ray diffraction and optical microscopy. The (110) and (100) texture were observed in the nickel coatings. The orientation densities of (110) and (100) textures are dependent on coating thickness (plating time) and cathode current density. Based on the morphology, microstructure and texture of the coatings, the electrocrystallization of nickel electrodeposits has been analyzed according to the depositing conditions. The orientation crystal growth for the nickel electrodeposition has been discussed and used to explain the formation of (110) and (100) textures.

9:30 AM L2.4 
LATTICE PARAMETER DETERMINATION OF TEXTURED Co81-xCr15PtxTa4 THIN FILMS. B. Lu , D.E. Laughlin, D.N. Lambeth, Carnegie Mellon University, Data Storage System Center, Pittsburgh, PA; S.D. Harkness, W.A. Lewis, Intevac, Vacuum Systems Division, Santa Clara, CA.

The addition of Pt to hcp-CoCrTa alloy has become a popular method to increase the magnetocrystalline anisotropy. An increased anisotropy provides for higher coercivities and better thermal stability as grain size is reduced to improve the media signal to noise ratio. However, as the Pt composition is increased the lattice parameters of the CoCrPtTa alloy vary. This can lead to lattice mismatch between the underlayer and the magnetic layer, resulting in poor epitaxial growth, degraded crystallographic texture, and increased defect density in the magnetic layer. Hence, it is important to understand how the lattice parameters of CoCrPtTa thin films vary with Pt content so that the underlayer lattice parameters can be appropriately chosen. In this work, the lattice parameters of textured Co81-xCr15PtxTa4 thin films were determined by a combination of x-ray diffraction and electron diffraction techniques. The Co-alloy thin films were sputter deposited onto NiP/Al substrates by production process. Strong (0002) texture was obtained. This allows excellent determination of the c-axis by x-ray diffraction -2 scan. But because of the strong (0002) texture, the a-axis cannot be detected by x-ray diffraction unless using a geometric method, which determines a d-spacing consisting both c-axis and a-axis. However, because of the thinness of the CoCrPtTa layer (e.g. 15 nm) and the amorphous NiP substrate it is difficult to obtain reliable signals. Therefore, an electron diffraction method on plan-view samples was adopted to measure directly the a-axis. By digitizing the electron diffraction patterns the a-axis could be determined within an error of 0.001 nm. The data show that both the c-axis and a-axis increase linearly with Pt composition. The c/a ratio of the Co81-xCr15PtxTa4 thin films remains nearly constant (1.61) for 1<x<6, which is slightly smaller than that of hcp Co (1.63).

10:15 AM *L2.5 
CRYSTALLOGRAPHIC TEXTURE AND MAGNETO-OPTIC PROPERTIES OF (Mn,Cr)Bi THIN FILMS. Tim Sands , Prabhakar Bandaru, Dept of Materials Science and Mineral Engineering, University of California, Berkeley, CA.

Thin films of MnBi possess several of the properties that are required for application as short-wavelength magneto-optic recording media, including large Kerr rotation and a high degree of perpendicular magnetic anisotropy. However, the coupling of the principal magnetic transition with a first-order lattice transition at 360C, and the microstructural nonuniformity associated with a large lateral grain size have been recognized as impediments to achieving acceptable thermomagnetic recording performance. This talk will describe the results of studies of the microstructural evolution of MnBi films and the effects of Cr substitution on the microstructure and magneto-optic properties. Mn/Bi bilayers and Cr/Mn/Bi trilayers were deposited by electron-beam evaporation onto fused silica substrates. X-ray diffraction and in situ transmission electron microscopy annealing studies show that the MnBi phase nucleates and grows topotactically into the fiber-textured Bi layer during the initial stages of the post-growth heat treatment. Fully annealed MnBi and (Mn,Cr)Bi films exhibit strong (000l) fiber texture, with a rocking curve FWHM of 1 degree. The substitution of 5-15% Cr for Mn decouples the structural and magnetic transformations, reducing the effective Curie temperature from 360C to 250C, below the MnBi-Bi eutectic temperature of 270C. The Kerr rotation spectra show maxima of 0.8 degrees at 370 nm, matching well with the range of emission wavelengths of GaN-based laser diodes.

10:45 AM L2.6 
TENSILE AND COMPRESSIVE INTERFACE STRESS IN Cu/Ni AND Au/Ni MULTILAYERS. K.O. Schweitz , J. Bottiger, J. Chevallier, Institute of Physics and Astronomy, University of Aarhus, DENMARK; R. Feidenhans'l, M.M. Nielsen, F.B. Rasmussen, Condensed Matter Physics and Chemistry Dept., Ris National Laboratory, Roskilde, DENMARK; W. Matz, N. Schell, Research Center Rossendorf, Dresden, GERMANY.

In this paper, we present the first studies of the interface stress in a multilayer with coherent interfaces, Cu/Ni, and in Au/Ni multilayers with incoherent interfaces. The <111>-textured multilayers were deposited by use of DC-magnetron sputtering and bulk and interface stresses were obtained from X-ray diffraction and measurements of substrate curvatures. The interface stress in Cu/Ni multilayers was found to be 0.770.19 J/m2, the first reported experimental measured tensile interface stress in a metallic multilayer. The coherent/incoherent transition in Cu/Ni multilayers is observed at a critical bilayer repeat length of about 10.5 nm, in agreement with theory. The interface stress in Au/Ni multilayers is found to be compressive, in agreement with theory, but the value of 8.460.99 J/m2 is much larger than both the prediction by theory and more than twice as large as values reported for other systems. For the sample having the smallest repeat length, interface roughness and lattice parameters show that this sample has weakly cumulative interfaces and a strong coherency effect, in contrast to samples with larger repeat lengths. This explains the observed deviation of the interface stress. The Ni layer in the Au/Ni system shows an apparent breakdown of the bulk Poissonís effect. In both systems, the high level of strain makes it necessary to include third-order stiffness coefficients in calculating the stress in the strong <111>-textured Cu/Ni and Au/Ni multilayers.

11:00 AM L2.7 
DETERMINATION OF INTERFACE STRESS FROM TRANSMISSION X-RAY DIFFRACTION OF FREESTANDING SILVER/NICKEL MULTILAYERS. Ingrid X. Shao and Robert C. Cammarata, The Johns Hopkins University, J.E. Bonevich, Daniel Josell , National Institute of Standards and Technology, Gaithersburg, MD.

It is well known that the stress associated with deposition of thin film coatings can have a significant effect on the coating properties and lifetime. However, as the individual layers become thinner, the stress associated with the presence of internal interfaces, and derivable front equilibrium thermodynamics, can become significantly larger than the deposition stress. The thermodynamic quantity that detemines the magnitude of this stress is the interface stress. It equals the derivative of the free energy of a fixed number of atoms on an interface with respect to equal in-plane strains of the layers immediately adjacent to the interface. It thus represents the ability of the system to lower its free energy by reducing the free energy of the interface at the expense of added strain energy within the adjacent material. We have measured the interface stress of interfaces between (111) nickel and silver layers using transmission x-ray diffraction studies of freestanding silver/nickel multilayers. The interface stress was determined from the dependence of the in-plane silver and nickel lattice constants on the thickness of the silver/nickel bilayers and the elemental stiffness tensors. Past measurements of interfacial stress, which included similar experiments with multilayer thin films still attached to substrates, required additional studies of substrate curvature, and the stiffness tensor of the substrate, to correct for forces applied by the substrate.

11:15 AM L2.8 
INTERNAL STRESS IN SPUTTERED SILVER NICKEL THIN FILMS AND MULTILAYERS: SPUTTERING PRESSURE AND THICKNESS EFFECTS. Catherine Pélissonnier-Grosjean, Patrice Gergaud , Olivier Thomas, MATOP, Aix-Marseille University, FRANCE; Hua Yang, Amarante J. Bottger, LMS, Delft University of Technology, THE NETHERLANDS; Per Sandstrm, Jan Eric Sundgren, DPMT, Linkoping University, SWEDEN.

Nanometer thick films are often in a state of high residual stress. This may strongly influence physical properties such as magnetic anisotropy.