Periodic Co/Nb pseudo spin valve for cryogenic memory

• Nikolay Klenov,
• Yury Khaydukov,
• Sergey Bakurskiy,
• Roman Morari,
• Igor Soloviev,
• Vladimir Boian,
• Thomas Keller,
• Mikhail Kupriyanov,
• Anatoli Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2019, 10, 833–839, doi:10.3762/bjnano.10.83

• memory applications. As a basis for a weak link we propose to use a periodic structure composed of ferromagnetic (F) layers spaced by thin superconductors (s). Our calculations based on the Usadel equations show that switching from parallel (P) to antiparallel (AP) alignment of neighboring F layers can

• the feasibility of controllable switching between AP and P states through the whole periodic structure, we prepared a superlattice [Co(1.5 nm)/Nb(8 nm)/Co(2.5 nm)/Nb(8 nm)]6 between two superconducting layers of Nb(25 nm). Neutron scattering and magnetometry data showed that parallel and antiparallel

• ], and also due to compatibility with a number of quantum and neuromorphic computers under development [2][3][4]. However the lack of cryogenic memory elements (including synapses) with sufficiently fast switching between stable states and sufficiently small energy dissipation is still the main obstacle

Coexisting spin and Rabi oscillations at intermediate time regimes in electron transport through a photon cavity

• Vidar Gudmundsson,
• Hallmann Gestsson,
• Nzar Rauf Abdullah,
• Chi-Shung Tang,
• Andrei Manolescu and
• Valeriu Moldoveanu

Beilstein J. Nanotechnol. 2019, 10, 606–616, doi:10.3762/bjnano.10.61

• transport in the far-infrared (FIR) regime. The time-dependent electronic transport through a two-dimensional (2D) nanosystem patterned in a GaAs heterostructure, which is in turn embedded in a three-dimensional (3D) FIR photon cavity, generally displays three regimes: i) The switching transient regime in

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• function of temperature. PtSe2 nanosheet based humidity sensor: (a) Typical resistance versus relative humidity plot and (b) current–time (I–t) plot taken after switching 11% RH and 97% RH. The photodetector application of PtSe2 nanosheets: (c) I–V in dark conditions and with green LED light and (d

Integration of LaMnO_3+δ films on platinized silicon substrates for resistive switching applications by PI-MOCVD

• Raquel Rodriguez-Lamas,
• Dolors Pla,
• Odette Chaix-Pluchery,
• Benjamin Meunier,
• Fabrice Wilhelm,
• Andrei Rogalev,
• Laetitia Rapenne,
• Xavier Mescot,
• Quentin Rafhay,
• Hervé Roussel,
• Michel Boudard,
• Carmen Jiménez and
• Mónica Burriel

Beilstein J. Nanotechnol. 2019, 10, 389–398, doi:10.3762/bjnano.10.38

• and reduction of the power consumption. In this context, resistive switching memory chips emerge as promising candidates for developing new non-volatile memory modules. Manganites have received increasing interest as memristive material as they exhibit a remarkable switching response. Nevertheless

• technique. We have developed three different growth strategies with which we are able to tune the oxygen content and Mn oxidation state moving from an orthorhombic to a rhombohedral structure for the active LaMnO3+δ material. Furthermore, a good resistive switching response has been obtained for LaMnO3+δ

• -based devices fabricated using optimized growth strategies. Keywords: manganite; metal organic chemical vapour deposition (MOCVD); resistive switching; thin film; valence-change memory; Introduction Resistive switching (RS) denotes the phenomena occurring in capacitor-like heterostructures (metal

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• , electric anisotropy, splay elastic constant, switch-on time, and switch-off time. The shape and dimensions of the GO flakes were studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The influence of the GO concentration on the physical properties and switching process in the

• presence of the electric field was discussed. Keywords: graphene oxide; liquid crystal; nematic phase; switching; threshold voltage; Introduction Liquid crystals (LCs) are classified as a type of soft matter which are characterized by anisotropic molecules and a liquid-like fluidity behavior. Of all LC

• composites [11][12][13][14]. NLCs doped with graphene or carbon nanotubes show a faster response in electro-optical switching than pure liquid crystal compounds. This effect is caused by trapping of some free ion concentrations [15][16] or reduction in the rotational viscosity [17]. Furthermore, due to

Electrostatic force microscopy for the accurate characterization of interphases in nanocomposites

• Diana El Khoury,
• Richard Arinero,
• Jean-Charles Laurentie,
• Mikhaël Bechelany,
• Michel Ramonda and
• Jérôme Castellon

Beilstein J. Nanotechnol. 2018, 9, 2999–3012, doi:10.3762/bjnano.9.279

• lock-in amplifier (EG&G Instruments – Model 5302), locked at the double frequency of the AC-electrical excitation and an arbitrary function generator (Sony Tektronic – AFG310). A custom-made switching device was used to extract the 2ω component from the signal obtained during the second pass. A 5 V AC

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

Contactless photomagnetoelectric investigations of 2D semiconductors

• Marian Nowak,
• Marcin Jesionek,
• Barbara Solecka,
• Piotr Szperlich,
• Piotr Duka and
• Anna Starczewska

Beilstein J. Nanotechnol. 2018, 9, 2741–2749, doi:10.3762/bjnano.9.256

• . Results and Discussion Figure 5a shows the induced VPME response to the switching on and switching off of the sinusoidally modulated illumination of single-layer graphene with and without a magnetic field. The measured VPME responses are proportional to the magnetic field induction (Figure 5b) and to the

• electrostatically tunable carrier density. The charge carriers can change from electrons to holes with the application of an electrostatic gate. The switching takes place at the Dirac point, where the carriers have a minimum density. The gate voltage, Vg, induces a sheet carrier concentration approximated by [33

• the energy position of Fermi level and the switching between 2D electron and hole gases by changing the gate voltage. Taking into account the proportionality of the PME magnetic flux to the square of carrier mobility and lifetime presented above (Figure 2) (i.e., in the case of small values of μτ and

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• nanorods; Q-switching; saturable absorption; solid-state lasers; zinc oxide; Introduction Zinc oxide (ZnO) is a well-known II–IV group wide-bandgap semiconductor (Eg = 3.37 eV), possessing a hexagonal wurtzite-type (sp. gr. P63mc) structure with unit cell parameters a = 3.25 Å, c = 5.20 Å. In recent years

• with picosecond pulses resulting in Isat = 16 kW/cm2, which is close to our observations. Passive Q-switching by ZnO nanorods The laser experiments were performed with the NRs grown for 5 h, because they exhibited minimum insertion loss. Stable Q-switching was also observed for the NRs grown for 10 h

• scaling of the laser in the PQS regime was limited by the Q-switching instabilities arising for Pabs > 3.2 W due to the heating of the SA by the residual (non-absorbed) pump [22]. The pulse duration Δτ, determined as full width at half maximum (FWHM) and the pulse repetition frequency (PRF) for the PQS

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• magnetic heating contribution by using where C is the volumetric specific heat capacity of the sample, mf the dispersion mass, mMNPs is the iron mass diluted in the dispersion and ΔΤ/Δt is the maximal slope at initial time after switching on the heating AC field. In vitro experiments Cell culture. 4T1

Nanoantenna structures for the detection of phonons in nanocrystals

• Alexander G. Milekhin,
• Sergei A. Kuznetsov,
• Ilya A. Milekhin,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Alexander V. Latyshev,
• Volodymyr M. Dzhagan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2018, 9, 2646–2656, doi:10.3762/bjnano.9.246

• obtained for three different angles of incidence θ = 0, 25, and 50°. Since the longitudinal LSPR mode can be excited either by TE- (E0 II X) or TM-polarized (H0 II Y) waves, both geometries are considered in the simulations. Note that switching to the second derivative of d instead of the dipole moment

Effective sensor properties and sensitivity considerations of a dynamic co-resonantly coupled cantilever sensor

• Julia Körner

Beilstein J. Nanotechnol. 2018, 9, 2546–2560, doi:10.3762/bjnano.9.237

• magnetic properties. This led to the first time observation of magnetic switching of these individual Heusler nanoparticles at room temperature and with a comparatively simple setup (laser-deflection detection) [16]. Other experiments in magnetic force microscopy showed a likewise increase in sensitivity

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• coefficient of friction when switching from the 0° to the 90° direction, and this is evident especially for large values of Δ. The dependence of µs on the angle, instead, is more complex for Δ < 0.3, especially for the 3D FEM, where the interaction with the vertical stress distribution must also be taken into

Pinning of a ferroelectric Bloch wall at a paraelectric layer

• Vilgelmina Stepkova and
• Jiří Hlinka

Beilstein J. Nanotechnol. 2018, 9, 2356–2360, doi:10.3762/bjnano.9.220

• loop demonstrating switching of the Pt component of the Bloch wall located at a 1 nm thin SrTiO3 layer. The indicated value of the polarization Pt is averaged over the whole supercell shown in Figure 1b. Acknowledgements This work was supported by the Czech Science Foundation (project no. 15-04121S

Magnetism and magnetoresistance of single Ni–Cu alloy nanowires

• Andreea Costas,
• Camelia Florica,
• Elena Matei,
• Maria Eugenia Toimil-Molares,
• Ionel Stavarache,
• Andrei Kuncser,
• Victor Kuncser and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2018, 9, 2345–2355, doi:10.3762/bjnano.9.219

• , the magnetization reversal canb be described using the Stoner–Wohlfarth model [29][30]. Thus, if the field is applied along the easy axis (EA), the magnetization changes steeply its orientation along the EA at a switching field proportional to the anisotropy constant and inversely proportional to the

• decrease of the magnetization from positive to negative saturation, with the saturation field equating the switching field in parallel geometry. If the current flows along the EA, the resistivity is above the saturation field (θ = 90°) and at zero field (where the magnetization lies along the EA, due to

• perpendicular to the easy axis. The saturation field (approaching the switching field in case of the S–W model) decreases very slowly with the Ni composition, contrary to what would be expected from the composition dependence of the saturation magnetization and inverse proportionality of the switching field

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• the electrostatic integrity of the devices causes conventional doping to fail. Metal–Si contacts formed by, e.g., silicide formation [36] result in rather high Schottky-barriers at the source/drain-channel interfaces that deteriorate the switching behaviour and on-state performance. h-DFT calculations

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• between an LED and a photoconductive detector both based on GaN NWs [29]. The communication took place in free space. Using NWs located close to each other, the authors demonstrated a correlation between the LED on/off switching and the photodetector current variations. A waveguide for light channeling is

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement

• Nicolae Leopold,
• Andrei Stefancu,
• Krisztian Herman,
• István Sz. Tódor,
• Stefania D. Iancu,
• Vlad Moisoiu and
• Loredana F. Leopold

Beilstein J. Nanotechnol. 2018, 9, 2236–2247, doi:10.3762/bjnano.9.208

• addition of MgSO4 or Ca(NO3)2 in concentrations ranging from 10−4 –10−3 M to a cit-AgNP solution which already contains 1 mM NaCl, led to the switching on of the SERS effect and the recording of very intense SERS spectra of 10−9 M crystal violet. Accordingly, the intense SERS spectra of crystal violet

Influence of the thickness of an antiferromagnetic IrMn layer on the static and dynamic magnetization of weakly coupled CoFeB/IrMn/CoFeB trilayers

• Deepika Jhajhria,
• Dinesh K. Pandya and
• Sujeet Chaudhary

Beilstein J. Nanotechnol. 2018, 9, 2198–2208, doi:10.3762/bjnano.9.206

• lowering the spin torque critical current switching density [22][23]. For various other applications a fast relaxation is favored, e.g., in magnetoresistive heads [24][25]. The FM/AF exchange coupling is one of the approaches to tune the magnetization relaxation by enhancing the field linewidth ΔH and

High-throughput synthesis of modified Fresnel zone plate arrays via ion beam lithography

• Kahraman Keskinbora,
• Umut Tunca Sanli,
• Margarita Baluktsian,
• Corinne Grévent,
• Markus Weigand and
• Gisela Schütz

Beilstein J. Nanotechnol. 2018, 9, 2049–2056, doi:10.3762/bjnano.9.194

• redirected to higher orders including the 2nd and 3rd diffraction orders. 2nd order DE, which is almost 0 for a perfect 1:1 duty cycle (Supporting Information File 1, Figure S2), increases if the L:S ratio deviates from 1:1. The situation can be remedied relatively easily by switching to an SP-E process for

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• process and the task of the related functional molecular groups. Then, the frictional properties of these films in the different conformations (e.g., trans and cis) will be intensively studied to understand how this conformation switching affects energy dissipation. Multiscale bridging The current

Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition

• Irini Michelakaki,
• Nikos Boukos,
• Dimitrios A. Dragatogiannis,
• Spyros Stathopoulos,
• Costas A. Charitidis and
• Dimitris Tsoukalas

Beilstein J. Nanotechnol. 2018, 9, 1868–1880, doi:10.3762/bjnano.9.179

• embedded into a metal-oxide layer, result in a completely new behavior of resistive switching compared with pristine metal-oxide layers, which is important for operation and understanding of nonvolatile resistive random-access memory (ReRAM) [20]. Furthermore except of size, shape and structure of NPs, a

The role of the Ge mole fraction in improving the performance of a nanoscale junctionless tunneling FET: concept and scaling capability

• Hichem Ferhati,
• Fayçal Djeffal and
• Toufik Bentrcia

Beilstein J. Nanotechnol. 2018, 9, 1856–1862, doi:10.3762/bjnano.9.177

• investigated. Moreover, the impact of the Ge mole fraction in the proposed Si1−xGex source region on the electrical figures of merit (FoMs) of the transistor, including the swing factor and the ION/IOFF ratio is analyzed. It is found that the optimized design with 60 atom % of Ge offers improved switching

• , where the optimized design exhibits an improved switching behavior at the nanoscale level. These results make the optimized device suitable for designing digital circuit for high-performance nanoelectronic applications. Keywords: ambipolar conduction; heterojunctions; junctionless tunneling field

• structure demonstrates a superior switching behavior. This makes the optimized structure a potential alternative for providing energy-efficient transistors with suppressed ambipolar conduction for designing high-performance nanoelectronic circuits at low manufacturing cost. Numerical Simulations Figure 1

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• polarization of the conduction band. The heterostructures demonstrate a significant superconducting spin-valve effect, i.e., a complete switching on and off of the superconducting current flowing through the system by manipulating the mutual orientations of the magnetization of the F1 and F2 layers. The

• magnitude of the effect is doubled in comparison with the previously studied analogous multilayers with the F2 layer made of the strong ferromagnet Fe. Theoretical analysis shows that a drastic enhancement of the switching effect is due to a smaller exchange field in the heterostructure coming from the

• Heusler film as compared to Fe. This enables to approach an almost ideal theoretical magnitude of the switching in the Heusler-based multilayer with a F2 layer thickness of ca. 1 nm. Keywords: ferromagnet; proximity effect; spin valve; superconductor; Introduction Historically, the first concept to

Magnetic properties of Fe₃O₄ antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

• Juan L. Palma,
• Alejandro Pereira,
• Raquel Álvaro,
• José Miguel García-Martín and
• Juan Escrig

Beilstein J. Nanotechnol. 2018, 9, 1728–1734, doi:10.3762/bjnano.9.164

• presence of the ordered non-magnetic holes induces a demagnetization field distribution that changes the magnetization switching mechanisms [6], acting as pinning centers for domain walls [7], enhancing coercivity compared to that of the continuous film [8][9][10][11][12], and affecting the magnetic