Giant Magnetoresistance in FeMn/NiCoFe/Cu/NiCoFe Spin Valve Prepared by Opposed Target Magnetron Sputtering

2014 ◽  
Vol 979 ◽  
pp. 85-89 ◽  
Author(s):  
Ramli ◽  
Euis Sustini ◽  
Nurlaela Rauf ◽  
Mitra Djamal
Keyword(s):  
Magnetron Sputtering ◽  
Layer Thickness ◽  
Coercive Field ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Spin Valve ◽  
Ferromagnetic Layer ◽  
Vibrating Sample Magnetometer ◽  
Magnetoresistance Ratio ◽  
Scanning Electron

The giant magnetoresistance (GMR) effect in FeMn/NiCoFe/Cu/NiCoFe spin valve prepared by dc opposed target magnetron sputtering is reported. The spin valve thin films are characterized by Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and magnetoresistance ratio measurements. All measurements are performed in room temperature. The inserted 45 mm thickness FeMn layer to the NiCoFe/Cu/NiCoFe system can increase the GMR ratio up to 32.5%. The coercive field to be increased is compared with different FeMn layer thickness. Furthermore, the coercive field (Hc) decreases with increasing FeMn layer thickness. Magnitude of coercive field is 0.1 T, 0.09 T and 0.08 T for FeMn layer thickness is 30 nm, 45 nm and 60 nm, respectively. The FeMn layer is used to lock the magnetization in the ferromagnetic layer through the exchange anisotropy. This paper will describe the development of a GMR spin valve and its magnetic properties.

Giant Magnetoresistance Studies of NiFe-Based Spin-Valve Multilayers

1994 ◽  
Vol 343 ◽  
Author(s):  
Chien-Li Lin ◽  
John M. Sivertsen ◽  
Jack H. Judy
Keyword(s):  
Magnetic Field ◽  
Thermal Stability ◽  
Magnetic Properties ◽  
Multilayer Structure ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Spin Valve ◽  
Vibrating Sample Magnetometer ◽  
Recording Head ◽  
Annealing Experiments

ABSTRACTThe giant magnetoresistance in FeMn exchange-biased NiFe-based multilayer spin-valve structures prepared by rf-diode sputtering technique were studied. Experiments were performed on samples with different thicknesses of each layer in these multilayers. The magnetic properties were measured using a vibrating sample magnetometer and the giant magnetoresistance was measured using an in-line four-point magnetoresistance probe. A magnetoresistance of 6.5% in a magnetic field of less than 15 Oe was obtained in a Cu(30Å)/FeMn(150Å)/NiFe(50Å)/Co(15Å)/ Cu(20Å)/Co(15Å)/NiFe(60Å) multilayer structure at room temperature. Annealing experiments of these multilayers were performed to study the thermal stability during the recording head fabrication processes. No degradation in the magnetoresistance has been found for annealing these films at 230°C up to four hours.

Magnetoresistance ratio of more than 1% at room temperature in germanium vertical spin-valve devices with Co2FeSi

2021 ◽  
Vol 119 (19) ◽  
pp. 192404
Author(s):  
A. Yamada ◽  
M. Yamada ◽  
M. Honda ◽  
S. Yamada ◽  
K. Sawano ◽  
...  
Keyword(s):  
Room Temperature ◽  
Spin Valve ◽  
Magnetoresistance Ratio

Towards a Room Temperature Organic Spin Valve: Structural, Magnetic and Transport Properties of Fe3O4/PTCTE/Co Devices

2011 ◽  
Vol 1359 ◽  
Author(s):  
Mathieu Palosse ◽  
Elena Bedel-Pereira ◽  
François Olivié ◽  
Isabelle Séguy ◽  
Christina Villeneuve ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Current Distribution ◽  
Morphological Study ◽  
Room Temperature ◽  
Spin Valve ◽  
Vibrating Sample Magnetometer ◽  
Force Microscopy ◽  
Dc Sputtering ◽  
Ferromagnetic Electrodes ◽  
Atomic Force

ABSTRACTThis paper describes first steps in preparation of an organic spin valve based on a perylene derivative (PTCTE) sandwiched between magnetite (Fe3O4) and cobalt (Co) ferromagnetic electrodes. MgO(001)/Fe3O4/PTCTE (450 nm)/Co devices were prepared with different Co soft deposition methods: off-axis dc-sputtering or Joule evaporation. Vibrating Sample Magnetometer (VSM) studies of the Fe3O4/PTCTE/Co stacks evidence spin valve behavior with magnetically uncoupled electrodes. These results are correlated with a morphological study by atomic force microscopy (AFM) of each layer and tunneling AFM (TUNA) for the investigation of inhomogeneity of current distribution in the devices. Finally, macroscopic I-V characteristics performed on the same devices will be presented and compared with TUNA results.

Preparation of Hollow Nickel Ferrite Microspheres and their Magnetic Properties

2014 ◽  
Vol 1035 ◽  
pp. 488-491
Author(s):  
Jing Jing Li ◽  
Yun Zhao ◽  
Han Sheng Li ◽  
Qin Wu ◽  
Qing Ze Jiao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nickel Ferrite ◽  
Room Temperature ◽  
Solvothermal Method ◽  
Magnetization Measurement ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Hollow nickel ferrite microspheres with a diameter of about 1.5 to 2.5 μm were synthesized using an emulsion-based solvothermal method in combination with calcination at 550°C. The structures and morphologies of the nickel ferrite microspheres were characterized using an X-ray diffractometer, a transmission electron microscopy and a field emission scanning electron microscopy. Magnetization measurement was carried out using a vibrating sample magnetometer at room temperature. The saturation magnetization and coercivity of nickel ferrite microspheres could reach 19.41 emu/g and 202.28 Oe, respectively. Hollow nickel ferrite microspheres might be used as catalysts, magnetic materials and microwave absorbers.

Room temperature high Giant Magnetoresistance graphene based spin valve and its application for realization of logic gates

2020 ◽  
Vol 384 (7) ◽  
pp. 126171 ◽  
Author(s):  
Muzafar Gani ◽  
Khurshed A. Shah ◽  
Shabir A. Parah ◽  
Prabhakar Misra
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Spin Valve ◽  
Logic Gates

Design and Development of Magnetic Sensors Based on Giant Magnetoresistance (GMR) Materials

2006 ◽  
Vol 517 ◽  
pp. 207-211 ◽  
Author(s):  
Mitra Djamal ◽  
Darsikin ◽  
Togar Saragi ◽  
M. Barmawi
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Hysteresis Loop ◽  
Giant Magnetoresistance ◽  
Magnetic Sensors ◽  
Vibrating Sample Magnetometer ◽  
Design And Development

This paper describes magnetic sensors that have been developed in the last three years. GMR thin film materials have been successfully developed using unpinned CoFe/Cu/CoFe sandwiches on Si(100) substrate using a home built dc-opposed-target magnetron sputtering (OTMS). The magnetization of the sandwich is measured using hysteresis loop instrument, the Vibrating Sample Magnetometer (VSM). It was found that the phase of GMR was formed, with the MR ratio 15.76%.

Effect of inserting a ferromagnetic layer on the giant magnetoresistance of spin-valve sandwiches

2003 ◽  
Vol 93 (1) ◽  
pp. 325-329 ◽  
Author(s):  
Ming Xu ◽  
Yong Wang ◽  
Gang Xiong ◽  
Cuixiu Liu ◽  
Zhenhong Mai
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Ferromagnetic Layer

scholarly journals Giant magnetoresistance ratio in a current-perpendicular-to-plane spin valve based on an inverse Heusler alloy Ti2NiAl

2019 ◽  
Vol 10 ◽  
pp. 1658-1665
Author(s):  
Yu Feng ◽  
Zhou Cui ◽  
Bo Wu ◽  
Jianwei Li ◽  
Hongkuan Yuan ◽  
...  
Keyword(s):  
Transmission Coefficient ◽  
Heusler Alloy ◽  
Giant Magnetoresistance ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Spin Valve ◽  
Total Transmission ◽  
Higher Spin ◽  
Magnetoresistance Ratio ◽  
Current Perpendicular To Plane

A Ti2NiAl inverse Heusler alloy based current-perpendicular-to-plane (CPP) spin valve (SV) with various kinds of atomic terminated interfaces has been designed to explore the potential application of Heusler alloys in spintronics devices. By performing first principles calculations combined with the nonequilibrium Green’s function, it is revealed that spin magnetic moments of interfacial atoms suffer a decrease, and the electronic structure shows that the TiNiB-terminated structure possesses the largest interface spin polarization of ≈55%. Our study on spin-transport properties indicates that the total transmission coefficient at the Fermi level mainly comes from the contribution from the spin up electrons, which are regarded as the majority of the spin electrons. When the two electrodes of the CPP-SV device are in parallel magnetization configuration, the interface containing Ti and Ni atoms possesses a higher spin up transmission coefficient than the interface containing Ti and Al atoms. The device with the TiNiB-terminated interface possesses the largest magnetoresistance ratio of 3.28 × 105, and it has great application potential in spintronics devices.

Giant Magnetoresistance and Oscillation in Epitaxial Fe/Cr(111) Multilayers

1995 ◽  
Vol 384 ◽  
Author(s):  
Wen-C. Chiang ◽  
David V. Baxter ◽  
Yang-Tse Cheng
Keyword(s):  
Electron Beam ◽  
Layer Thickness ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Electron Beam Evaporation ◽  
Maximum Value ◽  
Oscillatory Coupling ◽  
Crystallographic Orientations

ABSTRACTWe report on the first studies of the giant magnetoresistance and oscillatory coupling in epitaxial Fe/Cr(111) multilayers. A series of samples were grown on hydrogen terminated Si(111) substrates at room temperature by UHV electron beam evaporation; with the thickness of Fe layer fixed at 30 Å, and the thickness of Cr layer varied from 10–47 Å. Giant magnetoresistance (GMR) is observed at 4.2 Å in these samples, with a maximum value of 13% for a Cr layer thickness of 13 Å. The associated oscillatory coupling is comparable to that reported in other crystallographic orientations in terms of both its period and phase.

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