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Ferromagnetic resonance and spin wave excitations in metallic glasses: The effects of thermal ageing and long-range magnetic ordering
Vol. 32, No. 12
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN THE J. PHYS. CHEM. SOUDS
directions of the deformation can be defmed. Finite strain expressions for these parameters are derived in terms of the Lagrangian strain tensor and the frameindifferent analogue of the Eulerian strain tensor. The expressions require for their evaluation the thermal expansion coefficients, the elastic moduli and their pressure and temperature derivatives, and the specific heat of the material, so that there are no arbitrary constants or “curve fitting”. In the case of cubic materials, it is possible to determine the unique Gruneisen parameter as a function of volume directly. For non-cubic materials, the volume dependence of the GrUneisen parameters is calculated using a quasi-harmonic finite strain model of equation of state. Numerical applications are given for some cubic and hexagonal metals and the results are discussed. Received 1 December 1978 17.
OXYGEN INTERACTION WITH Cu(100) STUDIED BY AES, ELS, LEED AND WORK FUNCTION CHAJ~TGES C. Benndorf, B. Egert, G. Keller, H. Seidel and F. Thieme, Institut für Physikalische Chenue der Universitat Hamburg, Laufgraben 24, 2000 Hamburg 13, West Germany.
The interaction of oxygen with Cu(100) surfaces was investigated from 85 to 800K by AES, ELS, LEED and work function change. At T> 300 K three different states of oxygen bonding are observed: (1) Chemisorption of oxygen (dosages up to 102 L), indicated by an increase of the work function change ~.Øand O(KLL) signal height. (2) Incorporation of oxygen into the Cu sublayer with further oxygen uptake accompanied by a decrease of and a shift of the O(KLL) Auger transition to lower energy (~ 102_106 L). (3) Growing of Cu(I) oxide, characterized by an increase of ~Ø, shifts of the oxygen and copper Auger transitions and significant changes in ELS and AES line shapes (>3 x 106 L, l0~—5x 10_i torT). At low ternperature (85 K) a second adsorbed oxygen species is detected. ~,
Received 26 January 1979 18.
FERROMAGNETIC RESONANCE AND SPIN WAVE EXCITATIONS IN METALLIC GLASSES: THE EFFECTS OF THERMAL AGEING AND LONG-RANGE MAGNETIC ORDERING Ion C. Baianu, Metal Physics, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, England; Kenneth A. Rubinson, University
V
Chemical Laboratory, Lensfield Road, Cambridge CB3 OHE, England; and John Patterson, Department of Metallurgy and Materials Science, Pembroke Street, Cambridge CB4 OHE, England. New ferromagnetic resonance experiments under degenerate resonance conditions are reported for FeNiPB metallic glass ribbons in annealed and polished samples. An interpretation of these experimental results in terms of established theories in Ferromagnetic and Spin Wave Resonance Spectroscopy (FSWR) is. proposed. The spin-wave analysis is used to interpret the effects of magnetic anisotropy on the lineshapes of metallic glasses before and after annealing. The conclusion is reached that a model of dipolar-coupled regions which assume a common resonance frequency band is appropriate in ferromagnetic metallic glasses. The role of surface pits scattering, microheterogeneities in chemical composition, clustering processes and longrange magnetic ordering in these systems is discussed in relation to the changes of glass properties produced by annealing. We also conclude that FSWR techniques are more sensitive than differential scanning calorimetry, X-ray scattering and static, magnetic techniques which are currently used to study structural relaxation in glasses. Received 12 September 1978 Revised 17 April 1979 19.
ELECTROMIGRATION OF GOLD (HIGH CONCENTRATION) IN LEAD D.A. Colopentia, H.B. Huntington and H. Nakajima, Physics Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.
The steady state method was used to study the in lead doped with 680 ppm electromigration of ‘95Au Au. In the temperature range 165—270°CAu migrates toward the anode, as in the case of more dilute solutions;but the effective charge in magnitude with decreasing temperature at aincreases faster rate than that observed for dilute Pb(Au) samples, so that the difference between the effective charge for the 680 ppm samples and that for dilute samples becomes larger as the solubility limit is approached. A simple model, which allows for formation of Au doublets in equilibrium with the singlets, predicts an apparent increase of Z* with concentration of impurity at lower temperatures somewhat greater than the observed effect. Received 18 December 1978 Revised 17 April 1979
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN THE J. PHYS. CHEM. SOUDS
directions of the deformation can be defmed. Finite strain expressions for these parameters are derived in terms of the Lagrangian strain tensor and the frameindifferent analogue of the Eulerian strain tensor. The expressions require for their evaluation the thermal expansion coefficients, the elastic moduli and their pressure and temperature derivatives, and the specific heat of the material, so that there are no arbitrary constants or “curve fitting”. In the case of cubic materials, it is possible to determine the unique Gruneisen parameter as a function of volume directly. For non-cubic materials, the volume dependence of the GrUneisen parameters is calculated using a quasi-harmonic finite strain model of equation of state. Numerical applications are given for some cubic and hexagonal metals and the results are discussed. Received 1 December 1978 17.
OXYGEN INTERACTION WITH Cu(100) STUDIED BY AES, ELS, LEED AND WORK FUNCTION CHAJ~TGES C. Benndorf, B. Egert, G. Keller, H. Seidel and F. Thieme, Institut für Physikalische Chenue der Universitat Hamburg, Laufgraben 24, 2000 Hamburg 13, West Germany.
The interaction of oxygen with Cu(100) surfaces was investigated from 85 to 800K by AES, ELS, LEED and work function change. At T> 300 K three different states of oxygen bonding are observed: (1) Chemisorption of oxygen (dosages up to 102 L), indicated by an increase of the work function change ~.Øand O(KLL) signal height. (2) Incorporation of oxygen into the Cu sublayer with further oxygen uptake accompanied by a decrease of and a shift of the O(KLL) Auger transition to lower energy (~ 102_106 L). (3) Growing of Cu(I) oxide, characterized by an increase of ~Ø, shifts of the oxygen and copper Auger transitions and significant changes in ELS and AES line shapes (>3 x 106 L, l0~—5x 10_i torT). At low ternperature (85 K) a second adsorbed oxygen species is detected. ~,
Received 26 January 1979 18.
FERROMAGNETIC RESONANCE AND SPIN WAVE EXCITATIONS IN METALLIC GLASSES: THE EFFECTS OF THERMAL AGEING AND LONG-RANGE MAGNETIC ORDERING Ion C. Baianu, Metal Physics, Cavendish Laboratory, Madingley Road, Cambridge CB3 OHE, England; Kenneth A. Rubinson, University
V
Chemical Laboratory, Lensfield Road, Cambridge CB3 OHE, England; and John Patterson, Department of Metallurgy and Materials Science, Pembroke Street, Cambridge CB4 OHE, England. New ferromagnetic resonance experiments under degenerate resonance conditions are reported for FeNiPB metallic glass ribbons in annealed and polished samples. An interpretation of these experimental results in terms of established theories in Ferromagnetic and Spin Wave Resonance Spectroscopy (FSWR) is. proposed. The spin-wave analysis is used to interpret the effects of magnetic anisotropy on the lineshapes of metallic glasses before and after annealing. The conclusion is reached that a model of dipolar-coupled regions which assume a common resonance frequency band is appropriate in ferromagnetic metallic glasses. The role of surface pits scattering, microheterogeneities in chemical composition, clustering processes and longrange magnetic ordering in these systems is discussed in relation to the changes of glass properties produced by annealing. We also conclude that FSWR techniques are more sensitive than differential scanning calorimetry, X-ray scattering and static, magnetic techniques which are currently used to study structural relaxation in glasses. Received 12 September 1978 Revised 17 April 1979 19.
ELECTROMIGRATION OF GOLD (HIGH CONCENTRATION) IN LEAD D.A. Colopentia, H.B. Huntington and H. Nakajima, Physics Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.
The steady state method was used to study the in lead doped with 680 ppm electromigration of ‘95Au Au. In the temperature range 165—270°CAu migrates toward the anode, as in the case of more dilute solutions;but the effective charge in magnitude with decreasing temperature at aincreases faster rate than that observed for dilute Pb(Au) samples, so that the difference between the effective charge for the 680 ppm samples and that for dilute samples becomes larger as the solubility limit is approached. A simple model, which allows for formation of Au doublets in equilibrium with the singlets, predicts an apparent increase of Z* with concentration of impurity at lower temperatures somewhat greater than the observed effect. Received 18 December 1978 Revised 17 April 1979