Structural, Magnetic, and Magneto-Optical Properties of Nanocrystalline Face Centered Cubic Co70Cr30/Pt Multilayers with Perpendicular Magnetic Anisotropy

2007 ◽  
Vol 7 (12) ◽  
pp. 4278-4284 ◽  
Author(s):  
E. Th. Papaioannou ◽  
M. Angelakeris ◽  
P. Poulopoulos ◽  
I. Tsiaoussis ◽  
C. Rüdt ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Multilayered Structure ◽  
Ultraviolet Region ◽  
Temperature Hysteresis ◽  
Face Centered Cubic ◽  
Geometry Configuration ◽  
Face Centered ◽  
Magneto Optic

Co70Cr30 alloyed layers are combined with extremely thin Pt layers in order to produce novel face-centered-cubic multilayered films to be considered as a potential perpendicular magnetic recording medium. The films were grown on Si, glass and polyimide substrates by e-beam evaporation at a temperature slightly higher than room temperature. The multilayered structure of the films was verified by X-ray diffraction experiments. Plane-view transmission electron microscopy images have revealed the formation of very small grains in the range of 7–9 nm. Hysteresis loops as a function of temperature were recorded via the magneto-optic Kerr effect in the polar geometry configuration. The system exhibits perpendicular magnetic anisotropy, which enhances with decreasing temperature. Hysteresis loops with a squareness of 1 and a coercivity of 1.45 kOe were obtained at 10 K. Furthermore, complete magneto-optic spectra of the films are recorded, showing a strong magneto-optic enhancement in the ultraviolet region at around 4.5 eV.

Magnetic and Magneto-Optic Properties of PtFe (001) and PtCo (001) Thin Films

1993 ◽  
Vol 313 ◽  
Author(s):  
Bruce M. Lairson ◽  
Mark R. Visokay ◽  
Robert Sinclair ◽  
Bruce M. Clemens
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Perpendicular Magnetic Anisotropy ◽  
Film Plane ◽  
Intermetallic Alloy ◽  
Face Centered Cubic ◽  
Visible Light Range ◽  
Face Centered ◽  
Co Alloys ◽  
Magneto Optic

ABSTRACTWe report on the magnetic and Magneto-optical properties of PtFe and PtCo intermetallic thin films when they have the CuAu(I) tetragonal structure and their crystallographic C axis is oriented out of the film plane. These films possess large perpendicular magnetic anisotropy energies. We observe changes in the Magneto-optic Kerr rotations of Pt-Fe and Pt-Co alloys associated with the formation of the uniaxial CuAu(I) crystal structure. In particular, we report the observation of up to 60% enhancement in the Magneto-optic Ken-rotation for ordered, epitaxial PtFe intermetallic alloy over that of the random face centered cubic alloy. This enhancement is wavelength dependent, with a peak in the visible light range at 2.0 eV.

Magnetic, Magneto-optic and Magnetotransport Properties of Nanocrystalline Co/Au Multilayers with Ultrathin Au Interlayers

2008 ◽  
Vol 8 (9) ◽  
pp. 4323-4328 ◽  
Author(s):  
E. Th. Papaioannou ◽  
V. Karoutsos ◽  
M. Angelakeris ◽  
O. Valassiades ◽  
P. Fumagalli ◽  
...  
Keyword(s):  
Multilayered Structure ◽  
Electron Beam Evaporation ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Stripe Domain ◽  
Kerr Rotation ◽  
Force Microscopy ◽  
Domain Structures ◽  
Face Centered ◽  
Magneto Optic

A series of nanocrystalline Co/Au multilayers with ultrathin Au interlayers was grown at room temperature by electron beam evaporation on Si(111), glass and polyimide substrates. X-ray diffraction measurements reveal a face centered cubic multilayered structure with very small nanograins within 7–10 nm in diameter. Magneto-optic polar Kerr effect experiments show an enhancement of the Kerr rotation around 3 eV as the Au interlayer thickness increases. The experimental data are interpreted with the help of simulated Kerr spectra. The magnetization curves and magnetic force microscopy images indicate the existence of perpendicularly magnetized stripe-domain structures at remanence. The magnitude of the magnetoresistance ratio reaches values of 0.4%. The investigation of the interplay between magnetic and magnetotransport properties demonstrates the contribution of the domain-wall spin-dependent scattering to the magnetoresistance.

Perpendicular Magnetic Anisotropy in Face-Centered Cubic (111) Co90Fe10/Pt Superlattices

2015 ◽  
Vol 6 ◽  
pp. 1-4 ◽  
Author(s):  
Jinjun Qiu ◽  
Zhaoliang Meng ◽  
Qi Jia Yap ◽  
Yi Yang ◽  
Ng Lay Geok Serene ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Perpendicular Magnetic Anisotropy ◽  
Face Centered Cubic ◽  
Face Centered

scholarly journals Magnetic Aspects and Large Exchange Bias of Ni0.9Co0.1/NiCoO Multilayers

Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 43-54
Author(s):  
Dimitrios I. Anyfantis ◽  
Nikos Kanistras ◽  
Camillo Ballani ◽  
Alexandros Barnasas ◽  
Vassilios Kapaklis ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Ultrathin Films ◽  
Exchange Bias ◽  
Kerr Effect ◽  
Quantum Interference ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Spin Reorientation ◽  
Temperature Hysteresis ◽  
Superconducting Quantum Interference Device

Ultrathin films of Ni0.9Co0.1 were grown by radio frequency magnetron sputtering. By means of a periodic natural oxidation procedure they were transformed into Ni0.9Co0.1/NiCoO multilayers. Room temperature hysteresis loops recorded via the magneto-optic Kerr effect have revealed over all in-plane magnetic anisotropy due to magnetostatic anisotropy. Mild thermal annealing at 250 °C enhanced a tendency for perpendicular magnetic anisotropy, mainly due to an increase of the uniaxial volume anisotropy term. Spin reorientation transition, exchange bias larger than 700 Oe, and strong coercivity enhancement were observed via a superconducting quantum interference device at low temperatures after field cooling.

Magnetic and magneto‐optic properties of thick face‐centered‐cubic Co single‐crystal films

1994 ◽  
Vol 64 (20) ◽  
pp. 2736-2738 ◽  
Author(s):  
T. Suzuki ◽  
D. Weller ◽  
C.‐A. Chang ◽  
R. Savoy ◽  
T. Huang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Face Centered Cubic ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Face Centered ◽  
Magneto Optic

Growth and Magnetism of Natural Multilayers

2011 ◽  
Vol 15 ◽  
pp. 95-103 ◽  
Author(s):  
Panagiotis Poulopoulos ◽  
S.D. Pappas ◽  
Vassilios Kapaklis ◽  
P.E. Jönsson ◽  
E.T. Papaioannou ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Room Temperature ◽  
Vacuum Chamber ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
Optical Recording ◽  
High Quality ◽  
Simple Method ◽  
Multilayered System ◽  
The Individual

. In this work, we present a simple method to fabricate high quality Ni/NiO multilayers with the use of a single magnetron sputtering head. Namely, at the end of the deposition of each single Ni layer, air is let to flow into the vacuum chamber through a leak valve. Then, a very thin NiO layer (~ 1nm) is formed by natural oxidation. The process is reproducible and the result is the formation of a multilayer with excellent layering. Magnetization hysteresis loops recorded at 5 K and room temperature reveal a tendency for perpendicular magnetic anisotropy as the thickness of the individual Ni layers decreases. It is shown that the Ni/NiO interface has sizeable positive surface/interface anisotropy, i.e. it favors the development of perpendicular magnetic anisotropy. This is rather unusual for a Ni-based multilayered system and may render Ni/NiO multilayers useful for magneto-optical recording applications.

Structure-Property Relationships in Sputtered Magneto-Optic Multilayers

1997 ◽  
Vol 3 (S2) ◽  
pp. 397-398
Author(s):  
R. Sinclair ◽  
G. A. Bertero ◽  
M.R. Visokay
Keyword(s):  
Polarized Light ◽  
Hysteresis Loops ◽  
Perpendicular Magnetic Anisotropy ◽  
High Resolution Electron Microscopy ◽  
Magnetic Multilayers ◽  
Information Storage ◽  
Inert Gases ◽  
Structure Property ◽  
Kerr Rotation ◽  
Magneto Optic

One technology for high-density information storage employs magneto-optic thin films. Key material properties include a large magneto-optic Kerr rotation of polarized light (especially in the blue wavelength range), high perpendicular magnetic anisotropy, good reflectivity and a large magnetic coercivity. These can be achieved in nano-scale magnetic multilayers (e.g., Co-Pt) in which one of the constituent layers is ferromagnetic. Naturally the magnetic properties can be manipulated to a great extent by the preparation conditions, and the microstructure is most readily revealed by cross-section high-resolution electron microscopy (HREM). In our work, extremely high quality multilayers were fabricated by sputtering using a variety of inert gases, and most notably the influence of interface sharpness on properties was assessed. Intermetallic compounds, which are essentially “natural” multilayers, were also extensively studied.Figure 1 shows magneto-optic Kerr rotation hysteresis loops for multilayers sputtered in 5 mtorr of either argon or the heavier xenon gas.

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