Structure and magnetic properties of ultrathin Ni films on Pt(111) with Co buffer layers

Abstract

The growth mode and the structure of ultrathin Ni films on Pt(111) with Co buffer layers were studied by low-energy electron diffraction (LEED) and Auger electron spectroscopy. The comparative study of the magnetic properties between Ni/ Pt͑111͒ and Ni/1 ML Co/ Pt͑111͒ was investigated by magneto-optical Kerr effect. The oscillation of the specular beam of LEED and the Auger uptake curve were used to calibrate the thickness of Ni overlayers and to study the growth mode of Ni thin films on 1 ML Co/ Pt͑111͒. The study of the alloy formation for Ni/1 ML Co/ Pt͑111͒ showed that the temperature for mixing Ni and Co in the upper interface without diffusing into the bulk of Pt is independent of the thickness of Ni overlayers. By further increasing the temperature, Co and Ni diffuse into Pt bulk simultaneously to form Co-Pt, Ni-Pt, and Ni-Co-Pt alloys. The temperature of the formation of these alloys is dependent on the Ni thickness. Studies of the magnetic properties showed that the easy axis of the magnetization changed from the cant to the out-of-plane direction when the Co buffer layer was inserted on Ni/ Pt͑111͒. The alloy formation causes some interesting changes in the polar Kerr signal. The enhancement in the out-of-plane magnetization of Ni/ Co/ Pt͑111͒ is mainly contributed by the formation of Co-Pt alloy.

Direct Evidence of Anomalous Interfacial Magnetization in Metamagnetic Pd doped FeRh Thin Films

“…This magnetization temperature trend is reminiscent of FM ordering. Combined with a low remnant magnetization and higher NSLD than for the rest of the film, this could be a signature of a Fe rich region being energetically favored at the interface or diffusion of Pt making FM FeRh(Pt,Pd) 32 35 36 . Such an enhanced interfacial magnetization was also shown by PNR measurements carried out by R. Fan et al on FeRh films grown on MgO 24 .…”

Alloy formation of Co/Ni/Pt(111)

“…The magnetic properties of CoNi/Pt multilayer have been studied by Krishnan et al [5], and they indicated that this system exhibits perpendicular magnetic anisotropy and is suitable for application in high density MO storage media. We have studied the structural and magnetic properties of Ni/Co/Pt(1 1 1) [6,7], and some interesting results were observed, such as a spin reorientation transition occurs when one monolayer (ML) Co buffer layer is inserted between Ni thin films and Pt(1 1 1) substrate. The magnetic properties of a ferromagnetic material are strongly related to the structure itself.…”

Enhancing silicide formation in Ni/Si(111) by Ag-Si particles at the interface

“…By implanting nitrogen under the critical conditions, the growth of metal-rich silicide phases is circumvented, as the Ni film converts to the amorphous NiSi phase during annealing 19 . Because of the interest in developing novel spintronic devices, explorations directed toward attempting to combine the charge and spin degrees of freedoms have increased dramatically 12–28 . Based on a successful combination of a solution process and the efficient control of the electric potential for magnetism, a novel concept of electric-potential-tuned magnetic recording has been developed, resulting in the development of stable recording media with a high degree of writing ability 20 .…”