scholarly journals Memory and Spin Injection Devices Involving Half Metals

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
M. Shaughnessy ◽  
Ryan Snow ◽  
L. Damewood ◽  
C. Y. Fong
Keyword(s):  
Thin Film ◽  
Spin Injection ◽  
Anomalous Hall Effect ◽  
Crystal Form ◽  
Metallic Materials ◽  
Half Metallic ◽  
Half Metals ◽  
Spin Polarized ◽  
Film Form ◽  
Made In

We suggest memory and spin injection devices fabricated with half-metallic materials and based on the anomalous Hall effect. Schematic diagrams of the memory chips, in thin film and bulk crystal form, are presented. Spin injection devices made in thin film form are also suggested. These devices do not need any external magnetic field but make use of their own magnetization. Only a gate voltage is needed. The carriers are 100% spin polarized. Memory devices may potentially be smaller, faster, and less volatile than existing ones, and the injection devices may be much smaller and more efficient than existing spin injection devices.

Spin-injection Hall effect

2017 ◽  
Author(s):  
J. Wunderlich ◽  
K. Olejník ◽  
L. P. Zârbo ◽  
V. P. Amin ◽  
J. Sinova ◽  
...  
Keyword(s):  
Hall Effect ◽  
Spin Injection ◽  
Anomalous Hall Effect ◽  
Relative Strength ◽  
Spin Hall Effect ◽  
Quasi Particle ◽  
Hall Effects ◽  
Spin Polarized ◽  
Inverse Spin Hall Effect ◽  
Current Flows

This chapter discusses the Spin-injection Hall effect (SiHE), another member of the spin-dependent Hall effects that is closely related to the anomalous Hall effect (AHE), the spin Hall effect (SHE), and the inverse spin Hall effect (iSHE). The microscopic origins responsible for the appearance of spin-dependent Hall effects are due to the spin-orbit (SO) coupling-related asymmetrical deflections of spin carriers. Depending on the relative strength of the SO coupling compared to the energy-level broadening of the quasi-particle states due to disorder scattering, scattering-related extrinsic mechanisms or intrinsic band structure-related deflection dominate the spin-dependent Hall response. Both the iSHE and the SiHE require spin injection into a nonmagnetic system. Similar to the AHE, a spin-polarized charge current flows in the case of the SiHE and the SO coupling generates the spin-dependent Hall signal.

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.

scholarly journals Synthesis, structure, magnetic and half-metallic properties of Co2−x Ru x MnSi (x = 0, 0.25, 0.5, 0.75, 1) compounds

IUCrJ ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 113-120 ◽  
Author(s):  
H. P. Zhang ◽  
W. B. Liu ◽  
X. F. Dai ◽  
X. M. Zhang ◽  
H. Y. Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Curie Temperature ◽  
Single Phase ◽  
Metallic Materials ◽  
Heusler Compounds ◽  
Half Metallic ◽  
Half Metals ◽  
Treatment Conditions ◽  
Wide Range

A series of Co2−x Ru x MnSi (x = 0, 0.25, 0.5, 0.75, 1) Heusler compounds were successfully synthesized. The heat-treatment conditions were crucial to make the materials form a single phase with a Heusler structure. With increasing Ru content, the half-metallic gap, lattice parameters and magnetization are continuously adjustable in a wide range. The Co2−x Ru x MnSi (x = 0, 0.25) compounds are rigorous half-metals and show a T 3 dependence of resistance at low temperature. The Co2−x Ru x MnSi (x = 0.5, 0.75, 1) Heusler compounds are the nearly half-metallic materials and show a semiconductive dependence of resistance at low temperature. The experimental magnetization is consistent with that in theory and follows the Slater–Pauling rule. The Curie temperature is higher than 750 K for all Co2−x Ru x MnSi Heusler compounds.

ELECTRICAL SPIN INJECTION FROM AN IRON-RICH IRON–PLATINUM THIN FILM INTO GALLIUM ARSENIDE

2008 ◽  
Vol 17 (01) ◽  
pp. 105-109
Author(s):  
ASAWIN SINSARP ◽  
TAKASHI MANAGO ◽  
FUMIYOSHI TAKANO ◽  
HIRO AKINAGA
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Optical Measurement ◽  
Light Emitting Diode ◽  
Spin Injection ◽  
Light Emitting ◽  
Iron Platinum ◽  
Spin Polarized ◽  
Out Of Plane ◽  
Electrical Spin

We fabricated an FePt / MgO tunneling junction ( Fe 55 atomic %) on a GaAs -based light-emitting-diode structure. The out-of-plane magnetization of the FePt thin film was confirmed by a magneto-optical measurement. The electrical spin injection from FePt into GaAs at room temperature was studied using the technique of spin-polarized electroluminescence. The spin polarization of the injected electrons under the magnetic field of 1 T was at least 6.0%. The remnant polarization at 0 T, which indicates the spin injection without a magnetic field, was at least 3.3%.

scholarly journals Preparation and physical properties of a Cr3Al film with a DO3 structure

IUCrJ ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 552-557 ◽  
Author(s):  
W. Q. Zhao ◽  
X. F. Dai ◽  
X. M. Zhang ◽  
Z. J. Mo ◽  
X. T. Wang ◽  
...  
Keyword(s):  
Thin Film ◽  
Lattice Constant ◽  
Electrical Transport ◽  
Experimental Result ◽  
Half Metallic ◽  
Half Metal ◽  
Theoretical Investigations ◽  
Substrate Temperatures ◽  
Theoretical Results ◽  
Film Form

A Cr3Al compound with a DO3 structure has previously been predicted to be nearly half metal and a promising spintronics material; however, its synthesis has not been reported. Here, a Cr3Al compound with a DO3 structure is successfully prepared in thin-film form by the magnetron sputtering method. It was found that the substrate temperature is crucial to the atomic ordering, thin-film density and lattice constant. The lattice constant varies with different substrate temperatures and is smaller than the theoretical equilibrium lattice constant. Theoretical investigations on the electronic structures and magnetic properties indicate that the Cr3Al compound with a DO3 structure is a rare material with zero-gap half-metallic characteristics under an experimental lattice constant of 5.83 Å. The experimental result is in agreement with the theoretical results in magnetization, and the Cr3Al compound synthesized in this work exhibits semi-metallic-like electrical transport characteristics and positive magnetoresistance of greater than 2% in the temperature range 2–250 K.

SURFACE AND THIN FILM MAGNETISM WITH SPIN POLARIZED ELECTRONS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-9-C8-16 ◽  
Author(s):  
H. C. Siegmann ◽  
D. Mauri ◽  
D. Scholl ◽  
E. Kay
Keyword(s):  
Thin Film ◽  
Polarized Electrons ◽  
Spin Polarized ◽  
Thin Film Magnetism

Noise properties of thin-film Ni-P resistors embedded in printed circuit boards

2013 ◽  
Vol 61 (3) ◽  
pp. 731-735
Author(s):  
A.W. Stadler ◽  
Z. Zawiślak ◽  
W. Stęplewski ◽  
A. Dziedzic
Keyword(s):  
Thin Film ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Noise Component ◽  
Printed Circuit ◽  
Resistance Bridge ◽  
Different Types ◽  
Signal Path ◽  
Resistance Fluctuations ◽  
Made In

Abstract. Noise studies of planar thin-film Ni-P resistors made in/on Printed Circuit Boards, both covered with two different types of cladding or uncladded have been described. The resistors have been made of the resistive-conductive-material (Ohmega-Ply©) of 100 Ώ/sq. Noise of the selected pairs of samples has been measured in the DC resistance bridge with a transformer as the first stage in a signal path. 1/f noise caused by resistance fluctuations has been found to be the main noise component. Parameters describing noise properties of the resistors have been calculated and then compared with the parameters of other previously studied thin- and thick-film resistive materials.

scholarly journals Implantable Thin Film Devices as Brain-Computer Interfaces: Recent Advances in Design and Fabrication Approaches

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 204
Author(s):  
Yuhao Zhou ◽  
Bowen Ji ◽  
Minghao Wang ◽  
Kai Zhang ◽  
Shuaiqi Huangfu ◽  
...  
Keyword(s):  
Thin Film ◽  
High Resolution ◽  
Future Research ◽  
Nano Fabrication ◽  
Computer Interfaces ◽  
Continuous Progress ◽  
Open Mesh ◽  
Remarkable Progress ◽  
Thin Film Devices ◽  
Made In

Remarkable progress has been made in the high resolution, biocompatibility, durability and stretchability for the implantable brain-computer interface (BCI) in the last decades. Due to the inevitable damage of brain tissue caused by traditional rigid devices, the thin film devices are developing rapidly and attracting considerable attention, with continuous progress in flexible materials and non-silicon micro/nano fabrication methods. Therefore, it is necessary to systematically summarize the recent development of implantable thin film devices for acquiring brain information. This brief review subdivides the flexible thin film devices into the following four categories: planar, open-mesh, probe, and micro-wire layouts. In addition, an overview of the fabrication approaches is also presented. Traditional lithography and state-of-the-art processing methods are discussed for the key issue of high-resolution. Special substrates and interconnects are also highlighted with varied materials and fabrication routines. In conclusion, a discussion of the remaining obstacles and directions for future research is provided.

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