Giant magnetoresistance in La1−xSrxMnOzfilms near room temperature

1994 ◽  
Vol 65 (16) ◽  
pp. 2108-2110 ◽  
Author(s):  
H. L. Ju ◽  
C. Kwon ◽  
Qi Li ◽  
R. L. Greene ◽  
T. Venkatesan
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature

Thermal Characterization of Cu/CoFe Multilayer for Giant Magnetoresistive (GMR) Head Applications

2004 ◽  
Author(s):  
Y. Yang ◽  
M. Asheghi
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Boltzmann Transport Equation ◽  
Thermal Characterization ◽  
Disk Drive ◽  
Boltzmann Transport ◽  
Self Heating ◽  
Superlattice Structure ◽  
Metallic Ferromagnet

Giant Magnetoresistance (GMR) head technology is one of the latest advancement in hard disk drive (HDD) storage industry. The GMR head superlattice structure consists of alternating layers of extremely thin metallic ferromagnet and paramagnet films. A large decrease in the resistivity from antiparallel to parallel alignment of the film magnetizations can be observed, known as giant magnetoresistance (GMR) effect. The present work characterizes the in-plane electrical and thermal conductivities of Cu/CoFe GMR multilayer structure in the temperature range of 50 K to 340 K using Joule-heating and electrical resistance thermometry in suspended bridges. The thermal conductivity of the GMR layer monotonously increased from 25 Wm−1K−1 (at 55 K) to nearly 50 Wm−1K−1 (at room temperature). We also report the GMR ratio of 17% and a large negative magnetothermal resistance effect (GMTR) of 33% in Cu/CoFe superlattice structure. The Boltzmann transport equation (BTE) is used to estimate the GMR ratio, and to investigate the effect of repeats, as well as the spin-dependent interface and boundary scatting on the transport properties of the GMR structure. Aside from the interesting underlying physics, these data can be used in the predictions of the Electrostatic Discharge (ESD) failure and self-heating in GMR heads.

Giant Magnetoresistance in Single Layer and Multilayer Phase Separating Alloy Films

1993 ◽  
Vol 313 ◽  
Author(s):  
S. Hossain ◽  
A. Waknis ◽  
D. Seale ◽  
M. Tan ◽  
M.R. Parker ◽  
...  
Keyword(s):  
Thin Films ◽  
Field Dependence ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Single Layer ◽  
Multilayer Films ◽  
Equilibrium Conditions ◽  
Ferromagnetic Layers ◽  
Novel Processing ◽  
New Phase

ABSTRACTThe phenomenon of giant magnetoresistance (GMR), previously measured only in multilayer films comprising ferromagnetic layers separated by nonmagnetic spacers, has recently been observed in single layer ‘granular’ alloy thin films prepared by cosputtering a ferromagnet and a nonmagnet which tend to phase separate (cluster) under equilibrium conditions. We have systematically studied the magnetoresistance of two new phase separating GMR systems (Ni66Fe16Co18-Ag and Co9oFelo-Ag) both of which exhibit large room temperature GMR (>11% and >14%, respectively). We have also attempted to influence the details of the field dependence of the magnetoresistance in the previously studied Co-Ag system by employing novel processing methods including interrupted sputtering and layering of the Co-Ag alloy with Cu spacers.

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

Giant Magnetoresistance in Hybrid Magnetic Nanostructures Including Both Layers and Clusters

1995 ◽  
Vol 384 ◽  
Author(s):  
P.A. Schroeder ◽  
P. Holody ◽  
R. Loloee ◽  
J. L. Duvail ◽  
A. BarthÉlemy ◽  
...  
Keyword(s):  
Field Dependence ◽  
Temperature Sensitivity ◽  
Magnetization Reversal ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Magnetic Nanostructures ◽  
Squid Magnetometer ◽  
Band Model ◽  
Superparamagnetic Behaviour ◽  
Discontinuous Nature

ABSTRACTEarly experiments to define oscillations in the CIP magnetoresistance (CIP-MR) of Ag/Co analogous to those for tcu < 5nm in Cu/Co were unsuccessful. The MR in this region was very small. Later experiments by Araki using thin (0.6nm ) Co layers produced much larger MRs and lead us to look at the MRs of similar samples more closely. We conclude that the large MR of such samples is associated with the discontinuous nature of the Co layers. The object of the present paper is to combine the high MR associated with the thin Co layers with the field dependence governed by the magnetization reversal in thick, and magnetically soft permalloy (Py) layers. We have measured the CIP-MR of sputtered samples of the [Co(O.4 nm)/Ag(tAg)/Py(tpy)/Ag(tAg)]×15 system with tAg ranging from 1.05 to 4nm and with tpy = 2 or 4nm. We obtain MRs at 4.2K as large as 35% in less than 100e with slopes as high as 5%/Oe. With CPP measurements slopes as high as 10%/Oe have been obtained. Squid magnetometer measurements indicate that, as the temperature increases, there is a crossover to superparamagnetic behaviour and a resulting gross deterioration of the MR slopes at room temperature. Efforts to increase the room temperature sensitivity are described. Detailed measurements of the CPP-MR of the [Co(0.4nm)/Ag(4nm)/Py(tpy)/Ag(4nm)]x20 series of multilayers are consistent with a two spin band model modified to take account of the granular nature of the Co.

Room temperature giant magnetoresistance in La1-xPbxMnO3

1995 ◽  
Vol 28 (8) ◽  
pp. 1743-1745 ◽  
Author(s):  
R Mahendiran ◽  
R Mahesh ◽  
A K Raychaudhuri ◽  
C N R Rao
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature

Giant magnetoresistance at room temperature achieved in the ferromagnetic phase of powder La0.5Sr0.5MnO3

1998 ◽  
Vol 66 (1-4) ◽  
pp. 99-107 ◽  
Author(s):  
E. Dhahri ◽  
K. Guidara ◽  
A. Cheikhrouhou ◽  
J. C. Joubert ◽  
J. Pierre
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Ferromagnetic Phase

Giant Magnetoresistance Observed in (Fe,Mn)3O4Artificial Nanoconstrained Structures at Room Temperature

Nano Letters ◽  
2010 ◽  
Vol 10 (8) ◽  
pp. 2772-2776 ◽  
Author(s):  
Kazuya Goto ◽  
Teruo Kanki ◽  
Tomoji Kawai ◽  
Hidekazu Tanaka
Keyword(s):  
Giant Magnetoresistance ◽  
Room Temperature

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.

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