Magnetization study of Ni/Ag multilayers

The magnetic properties of Ni/Ag multilayers, prepared by evaporation in ultrahigh vacuum under controlled conditions, have been systematically studied by magnetic measurements. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction Jb and surface exchange interaction JS for various Ni layer thicknesses have been obtained.The magnetic properties of Ni/Ag multilayers, prepared by evaporation in ultrahigh vacuum under controlled conditions, have been systematically studied by magnetic measurements. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk exchange interaction Jb and surface exchange interaction JS for various Ni layer thicknesses have been obtained

Magnetic study in amorphous Gd0.7Zr0.3 alloys

We report here our magnetic study on amorphous Gd0.7Zr0.3 alloy. The magnetic saturation is difficult to obtain even for fields up to 50 kOe. This led us to the conclusion that ferromagnetic and antiferromagnetic clusters are present in this alloy. However, the presence of a well defined Tc indicate that the ferromagnetic clusters are dominant and he presence of the coherent anisotropy field can transform this type of magnetic ordering into a ferromagnetic domain structure. The thermomagnetization curve is found to obey the Bloch law, spin wave stiffness constant and the distance between nearest magnetic atoms were calculated from the experimental results.We report here our magnetic study on amorphous Gd0.7Zr0.3 alloy. The magnetic saturation is difficult to obtain even for fields up to 50 kOe. This led us to the conclusion that ferromagnetic and antiferromagnetic clusters are present in this alloy. However, the presence of a well defined Tc indicate that the ferromagnetic clusters are dominant and he presence of the coherent anisotropy field can transform this type of magnetic ordering into a ferromagnetic domain structure. The thermomagnetization curve is found to obey the Bloch law, spin wave stiffness constant and the distance between nearest magnetic atoms were calculated from the experimental results

Magnetic properties and interlayer coupling in Co/V multilayers

The magnetic properties of evaporated Co/V multilayer films have been studied by superconducting quantum interference device magnetometer and ferromagnetic-resonance (FMR). FMR has been used to study the interlayer exchange coupling and the FMR linewidth in Co/V multilayers at room temperature. Spin-waves resonance modes were observed in some Co/V multilayers and the relation of resonant field Hres with the mode number n obeys the so-called n2 law. The interlayer coupling constant was determined. The FMR linewidth, in parallel geometry, of the uniform mode was found to increase with decreasing Co thickness (10Å £ tCo £ 45Å) indicating that it corresponds to an interfacial effect

The strain-induced magnetic anisotropy of Ni81Fe19/W90Ti10 multilayers

The magnetic anisotropy results of Ni81Fe19 multilayers, prepared by DC sputtering in ultra high vacuum, were described on the basis of existing models. It is shown that magnetoelastic anisotropy energies Kme of the Ni81Fe19/W90Ti10 multilayers which have fcc (111) perfectly flat interfaces can be expressed with biaxial modulus, magnetostriction and lattice mismatch. In the incoherent state, the residual strain gives rise to a magnetic anisotropy which is proportional to the reciprocal of the magnetic layer thickness. The influence of roughness would decrease the anisotropy contribution

Magnetic properties of amorphous Fe80-xRxB20 ( with R= Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm )

Amorphous Fe80-xRxB20 alloys (with R=Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm ) have been prepared by melt spinning and their magnetic properties have been studied. The Gd moment at 4.2 K is found to be 7µB which agrees with the theoretical value indicating a collinear spin structure. The moments of the other rare-earth are lower than the theoretical value, implying a conical spin structure. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Fe-Fe and Fe-R atom pairs have also been evaluated.Amorphous Fe80-xRxB20 alloys (with R=Pr, Nd, Sm, Gd, Dy, Ho, Er and Tm ) have been prepared by melt spinning and their magnetic properties have been studied. The Gd moment at 4.2 K is found to be 7µB which agrees with the theoretical value indicating a collinear spin structure. The moments of the other rare-earth are lower than the theoretical value, implying a conical spin structure. The mean-field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Fe-Fe and Fe-R atom pairs have also been evaluated

Random anisotropy studies in amorphous Fe80-x+x' Hox B20-x' alloys (0

In this paper, we have carried out a systematic study of the exchange and anisotropy effects on magnetic behavior of amorphous Fe80-x+x' Hox B20-x' (0<x<17; 0<x'<4) alloys. Primary analysis of magnetization data have led to the conclusion that the holmium magnetic structure is collinear. Exchange parameters, governing the magnetic ordering of our alloys, have been calculated from both mean field theory and high-field magnetization analyses. Study of the magnetization using the Chudnovsky's real space model has allowed us to determine the overall anisotropy constant, KL, from which we have determined, separately, the anisotropy energies for the iron and the holmium sublattices. Comparison of these two parameters to the exchange energies shows that the anisotropy to exchange ratio is small in these alloys.In this paper, we have carried out a systematic study of the exchange and anisotropy effects on magnetic behavior of amorphous Fe80-x+x' Hox B20-x' (0<x<17; 0<x'<4) alloys. Primary analysis of magnetization data have led to the conclusion that the holmium magnetic structure is collinear. Exchange parameters, governing the magnetic ordering of our alloys, have been calculated from both mean field theory and high-field magnetization analyses. Study of the magnetization using the Chudnovsky's real space model has allowed us to determine the overall anisotropy constant, KL, from which we have determined, separately, the anisotropy energies for the iron and the holmium sublattices. Comparison of these two parameters to the exchange energies shows that the anisotropy to exchange ratio is small in these alloys

Consequences of divorce-based father absence during childhood for young adult well-being and romantic relationships

Objective: This research explores the implications of father absence due to divorce on young adults' well‐being and romantic relationships. Background: Studies have demonstrated the negative implications of father absence, a common consequence of divorce, on children's development. However, previous research has not systematically compared complete versus partial father absence. Method: Young adults who, as children, experienced complete (n = 38) or partial (n = 41) father absence were compared with 40 participants in a father‐presence control group. Results: Compared with those in the control group, young adults in the partial father‐absence group reported higher psychopathology and maternal overprotection, and lower maternal care, romantic intimacy, commitment, and passion. Under elevated maternal care, the partial‐absence group reported lower dyadic adjustment and consolidated sense of identity. Participants in the complete‐absence group reported higher self‐criticism and maternal overprotection and lower maternal care than controls. Conclusion: Partial father absence might have particularly pernicious consequences for young adults' well‐being. Implications: Clinical and public policy implications are discussed

Contribution of magnons to the properties of [Co/Ag] super lattice

In this work we study the elementary excitations and the magnetic properties of super lattice [Co/Ag]. The study is obtained in framework of the Heisenberg model for a ferromagnetic system made of N atomic planes. The exchange and the dipolar interactions, the magneto-crystalline anisotropy and surface anisotropy are all taking in account. In the presence of the exchange alone, the analytical expressions of the excitation spectrum  and the magnetization per spin =  are obtained using the Green function formalism. The values of the exchange integrals deduced from the comparison of  with experimental measurements are in good agreement with results of previous studies for analogous magnetic super lattices. A numerical study of the combined effect of dipolar interactions and surface anisotropy is also reported

Magnetic and non magnetic thickness effect on the exchange integrals in Co/Pt multilayers

In this paper, we report a theoretical study of elementary magnetic excitation properties of Co(tCo)/Pt(tPt) multilayers. We establish the corresponding spin hamiltonian by including exchange interactions, surface anisotropy and dipolar interactions. This hamiltonian is treated by Green’s function method. The calculated magnetization for various values of the magnetic layer thickness (tCo) as well as those of the non-magnetic one (tPt) according to the temperature is in good agreement with the experimentally measured one for these thicknesses and temperature. The deduced exchange integral values are satisfactory in agreement with the values known for 3d transition metals like cobalt

Magnetic properties in amorphous Co95­xDyxZr5 thin films

Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented.Amorphous Co95-xDyxZr5 thin films were prepared by RF sputtering and their magnetic properties were studied as a function of temperature and for the composition range 0<x<30. The mean field theory has been used to explain the temperature dependence of the magnetization. The exchange interactions between Co-Co and Dy-Co atom pairs have been evaluated. The magnetic phase diagrams are presented