scholarly journals Exchange bias in Co/CoO core-shell nanowires: Role of antiferromagnetic superparamagnetic fluctuations

2009 ◽  
Vol 80 (6) ◽  
Author(s):  
Thomas Maurer ◽  
Fatih Zighem ◽  
Frédéric Ott ◽  
Grégory Chaboussant ◽  
Gilles André ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Core Shell ◽  
Shell Nanowires

TEM and SEM-CL Studies of SiC Nanowires

2010 ◽  
Vol 645-648 ◽  
pp. 387-390
Author(s):  
Francesca Rossi ◽  
Filippo Fabbri ◽  
Giovanni Attolini ◽  
Matteo Bosi ◽  
Bernard Enrico Watts ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Point Defects ◽  
Shell Structures ◽  
Core Shell ◽  
Silicon Substrates ◽  
Luminescence Enhancement ◽  
Sic Nanowires ◽  
Effective Role ◽  
Shell Nanowires

-SiC and -SiC/SiO2 core-shell nanowires (NWs) grown on silicon substrates by three different processes, based on the use of i) carbon monoxide, ii) silane with propane and iii) carbon tetrachloride precursors, are analysed by structural and optical techniques. Spectroscopic cathodoluminescence studies show a luminescence enhancement in core-shell structures, ascribed to an effective role of the shell as both carrier injecting barrier and passivation layer. In NWs grown using CCl4 precursor, a peculiar luminescence with dominant red component at about 2 eV has been detected and ascribed to point defects related to an unintentional oxygen incorporation.

The Role of Atomic Hydrogen in Ge/Si Core–Shell Nanowires

2014 ◽  
Vol 118 (35) ◽  
pp. 20710-20715 ◽  
Author(s):  
Jongseob Kim ◽  
Kyung Yeon Kim ◽  
Hyoung Joon Choi ◽  
Ki-Ha Hong
Keyword(s):  
Atomic Hydrogen ◽  
Core Shell ◽  
Shell Nanowires

Exchange Bias in Core–Shell Nanowires and Nanotubes

Exchange Bias ◽  
2017 ◽  
pp. 233-274
Author(s):  
Mariana P. Proenca ◽  
João Ventura
Keyword(s):  
Exchange Bias ◽  
Core Shell ◽  
Shell Nanowires

Role of Confinement on Carrier Transport in Ge–SixGe1–x Core–Shell Nanowires

Nano Letters ◽  
2011 ◽  
Vol 12 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Junghyo Nah ◽  
David C. Dillen ◽  
Kamran M. Varahramyan ◽  
Sanjay K. Banerjee ◽  
Emanuel Tutuc
Keyword(s):  
Carrier Transport ◽  
Core Shell ◽  
Shell Nanowires

One-Dimensional TiO2@GaON Core-Shell Nanowires with Controlled Shell Thickness from Atomic Layer Deposition for Stable and Efficient Photoelectrochemical Water Splitting

2019 ◽  
Author(s):  
Jiajia Tao ◽  
Hong-Ping Ma ◽  
Kaiping Yuan ◽  
Yang Gu ◽  
Jianwei Lian ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Band Gap ◽  
Water Splitting ◽  
Atomic Layer ◽  
Photoelectrochemical Water Splitting ◽  
Core Shell ◽  
Photoelectrochemical Performance ◽  
Highly Efficient ◽  
Layer Deposition ◽  
Shell Nanowires

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>

scholarly journals Broadband Meta‐Absorber with Au/Ni Core–Shell Nanowires for Solar Vapor Generator

2021 ◽  
Vol 5 (7) ◽  
pp. 2100185
Author(s):  
Soomin Son ◽  
Jaemin Park ◽  
Sucheol Ju ◽  
Daihong Huh ◽  
Junho Jun ◽  
...  
Keyword(s):  
Core Shell ◽  
Vapor Generator ◽  
Shell Nanowires

scholarly journals Exchange-bias and magnetic anisotropy fields in core–shell ferrite nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. G. Silva ◽  
J. Depeyrot ◽  
Yu. L. Raikher ◽  
V. I. Stepanov ◽  
I. S. Poperechny ◽  
...  
Keyword(s):  
Spin Glass ◽  
Magnetic Moment ◽  
Exchange Bias ◽  
Uniaxial Anisotropy ◽  
Thermal Fluctuations ◽  
High Amplitude ◽  
Spin Coupling ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

AbstractExchange bias properties of MnFe$$_2$$ 2 O$$_4$$ 4 @$$\gamma$$ γ –Fe$$_2$$ 2 O$$_3$$ 3 core–shell nanoparticles are investigated. The measured field and temperature dependencies of the magnetization point out a well-ordered ferrimagnetic core surrounded by a layer with spin glass-like arrangement. Quasi-static SQUID magnetization measurements are presented along with high-amplitude pulse ones and are cross-analyzed by comparison against ferromagnetic resonance experiments at 9 GHz. These measurements allow one to discern three types of magnetic anisotropies affecting the dynamics of the magnetic moment of the well-ordered ferrimagnetic NP’s core viz. the easy-axis (uniaxial) anisotropy, the unidirectional exchange-bias anisotropy and the rotatable anisotropy. The uniaxial anisotropy originates from the structural core–shell interface. The unidirectional exchange-bias anisotropy is associated with the spin-coupling at the ferrimagnetic/spin glass-like interface; it is observable only at low temperatures after a field-cooling process. The rotatable anisotropy is caused by partially-pinned spins at the core/shell interface; it manifests itself as an intrinsic field always parallel to the external applied magnetic field. The whole set of experimental results is interpreted in the framework of superparamagnetic theory, i.e., essentially taking into account the effect of thermal fluctuations on the magnetic moment of the particle core. In particular, it is found that the rotatable anisotropy of our system is of a uniaxial type.

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