scholarly journals From spin-polarized interfaces to giant magnetoresistance in organic spin valves

2014 ◽  
Vol 89 (11) ◽  
Author(s):  
Deniz Çakır ◽  
Diana M. Otálvaro ◽  
Geert Brocks
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valves ◽  
Spin Polarized

scholarly journals COMPARATIVE STUDY OF SPIN INJECTION AND TRANSPORT IN Alq3 AND Co–PHTHALOCYANINE-BASED ORGANIC SPIN VALVES

SPIN ◽  
2014 ◽  
Vol 04 (02) ◽  
pp. 1440009 ◽  
Author(s):  
SAYANI MAJUMDAR ◽  
SUKUMAR DEY ◽  
HANNU HUHTINEN ◽  
JOHNNY DAHL ◽  
MARJUKKA TUOMINEN ◽  
...  
Keyword(s):  
Single Molecule ◽  
Giant Magnetoresistance ◽  
Chemical Reactivity ◽  
Spin Injection ◽  
Spin Valve ◽  
Spin Valves ◽  
Half Metallic ◽  
High Expectations ◽  
Spacer Layer ◽  
Spin Polarized

Recent experimental reports suggest the formation of a highly spin-polarized interface ("spinterface") between a ferromagnetic (FM) Cobalt ( Co ) electrode and a metal-phthalocyanine (Pc) molecule. Another report shows an almost 60% giant magnetoresistance (GMR) response measured on Co / H 2 Pc -based single molecule spin valves. In this paper, we compare the spin injection and transport properties of organic spin valves with two different organic spacers, namely Tris(8-hydroxyquinolinato) aluminum ( Alq 3) and CoPc sandwiched between half-metallic La 0.7 Sr 0.3 MnO 3 (LSMO) and Co electrodes. Alq 3-based spin valves exhibit clear and reproducible spin valve switching with almost 35% negative GMR at 10 K, in accordance with previous reports. In contrast, cobalt-pthalocyanine ( CoPc )-based spin valves fail to show clear GMR response above noise level despite high expectations based on recent reports. Investigations of electronic, magnetic and magnetotransport properties of electrode/spacer interfaces of LSMO/ CoPc / Co devices offer three plausible explanations for the absence of GMR: (1) CoPc films are strongly chemisorbed on the LSMO surface. This improves the LSMO magnetic properties but also induces local traps at the LSMO interface for spin-polarized charge carriers. (2) At the Co / CoPc interface, diffusion of Co atoms into the organic semiconductor (OS) layer and chemical reactivity between Co and the OS deteriorates the FM properties of Co . This renders the Co / CoPc interface as unsuitable for efficient spin injection. (3) The presence of heavy Co atoms in CoPc leads to large spin–orbit coupling in the spacer. The spin relaxation time in the CoPc layer is therefore considerably smaller compared to Alq 3. Based on these findings, we suggest that the absence of GMR in CoPc -based spin valves is caused by a combined effect of inefficient spin injection from FM contacts and poor spin transport in the CoPc spacer layer.

Piezoelectric enhancement of giant magnetoresistance in spin-valves with different magnetic anisotropies

2013 ◽  
Vol 113 (2) ◽  
pp. 023911 ◽  
Author(s):  
Syed Rizwan ◽  
S. Zhang ◽  
Tian Yu ◽  
Y. G. Zhao ◽  
X. F. Han
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valves

An origin of asymmetry of giant magnetoresistance loops in spin valves

2019 ◽  
Vol 470 ◽  
pp. 147-150
Author(s):  
A.S. Kurenkov ◽  
G.V. Babaytsev ◽  
N.G. Chechenin
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valves

Polycrystalline current-perpendicular-to-plane giant magnetoresistance pseudo spin-valves using Co2Mn(Ga0.25Ge0.75) Heusler alloy

2013 ◽  
Vol 114 (5) ◽  
pp. 053910 ◽  
Author(s):  
Ye Du ◽  
T. M. Nakatani ◽  
Y. K. Takahashi ◽  
N. Hase ◽  
T. Furubayashi ◽  
...  
Keyword(s):  
Heusler Alloy ◽  
Giant Magnetoresistance ◽  
Spin Valves ◽  
Current Perpendicular To Plane

Angular dependence of giant magnetoresistance properties of exchange biased spin valves

1999 ◽  
Vol 85 (8) ◽  
pp. 5033-5035 ◽  
Author(s):  
Sining Mao ◽  
Martin Plumer ◽  
Anthony Mack ◽  
Zhijun Yang ◽  
Ed Murdock
Keyword(s):  
Angular Dependence ◽  
Giant Magnetoresistance ◽  
Spin Valves

scholarly journals Ab initio study of CPP transport in Fe/Cr/Fe trilayers: influence of transition metal impurities

2002 ◽  
Vol 746 ◽  
Author(s):  
Heike C. Herper ◽  
Peter Entel ◽  
Laszlo Szunyogh ◽  
Peter Weinberger
Keyword(s):  
Transition Metal ◽  
Transport Properties ◽  
Giant Magnetoresistance ◽  
Interlayer Exchange Coupling ◽  
Metal Impurities ◽  
Relativistic Spin ◽  
Spin Polarized ◽  
Transition Metal Impurities ◽  
Experimental Findings ◽  
Interlayer Exchange

ABSTRACTThe transport properties of Fe(001)/Cr/Fe(001) trilayers are discussed with respect to the influence of transition metal impurities in form of layers. We are able to show that the periodicity of the giant magnetoresistance is directly influenced by the interlayer exchange coupling (IEC). Furthermore, it is observed that the behavior of the IEC strongly depends on whether an impurity overlayer of Mn or V is used. It turns out that the size of the GMR is only little effected by 3d-transition metal impurities, which is in agreement with the experimental findings. The electronic and magnetic properties of the trilayers have been investigated within the fully relativistic, spin-polarized SKKR method and the LDA. The transport properties of the Fe/Cr/Fe systems have been derived from the fully relativistic spin-polarized Kubo-Greenwood equation.

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