Magnetization dynamics in dilute Pd1-xFex thin films and patterned microstructures considered for superconducting electronics
Motivated by recent burst of applications offerromagnetic layers in superconducting digital and quantum elements, we study the magnetism ofthin films and patterned microstructures of Pd0.99Fe0.01. In this dilutedferromagnetic system, a high-sensitivityferromagnetic resonance (FMR) experiment reveals spectroscopic signatures of re-magnetization and enables the estimation of thesaturation magnetization, theanisotropy field, and the Gilbert damping constant. The detailed analysis of FMRspectra links the observed unexpectedly high reducedanisotropy field (0.06 –0.14) with the internalanisotropy, points towards a cluster natu...
Source: Journal of Applied Physics - October 26, 2016 Category: Physics Authors: I. A. Golovchanskiy, V. V. Bolginov, N. N. Abramov, V. S. Stolyarov, A. Ben Hamida, V. I. Chichkov, D. Roditchev and V. V. Ryazanov Source Type: research
Investigation of reactive plasma species created in SO2 by an inductively coupled RF discharge in E- and H-mode
Opticalemission spectroscopy(OES) and mass spectrometry were used to investigate the gas phase and surface reactions in inductively coupled SO2plasma at variousradiofrequency discharge powers up to 1000 W and gaspressures from 30 to 100 Pa. At such conditions, theplasma was created either in E- or inH-mode. In the E-mode, extensiveradiation in theUV range was observed due to transitions of SO2 and SO molecules to the ground electronic states, whereas the otherspectral features were marginal. At elevated powers, an abrupt transition to theH-mode occurred, where the totalradiation increased for several orders of magnitude...
Source: Journal of Applied Physics - October 26, 2016 Category: Physics Authors: Rok Zaplotnik, Alenka Vesel and Miran Mozetic Source Type: research
The impact of voltage independent carriers on implied voltage measurements on silicon devices
The electrical performance asolar cell is determined from directmeasurements of the current voltage relationship, while the so-calledimplied current-voltagemeasurements are often performed to estimate the performance of partially processed samples. Implied current voltagemeasurements are commonly obtained from quasi steady state photoconductance and quasi steady statephotoluminescencemeasurements, where the implied voltage is inferred from the average excesscarrier density. As will be shown here, this approach can be problematic due to the presence of excess carriers thatdo not contribute to the terminal voltage. These car...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: M. K. Juhl and T. Trupke Source Type: research
Minimum entropy principle-based solar cell operation without a pn-junction and a thin CdS layer to extract the holes from the emitter
Thesolar cell does not use apn-junction to separateelectrons from holes, but uses an undopedCdS layer that isp-type inverted when attached to ap-type collector and collects the holes while rejecting the backflow ofelectrons and thereby prevents junction leakage. The operation of thesolar cell is determined by the minimumentropy principle of thecell and its external circuit that determines the electrochemical potential, i.e., the Fermi-level of the base electrode to the operating (maximum power point) voltage. It leaves theFermi level of the metal electrode of theCdS unchanged, sinceCdS does not participate in the photo-emf...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Karl W. B öer Source Type: research
Domain structure and electronic state in P3HT:PCBM blend thin films by soft X-ray resonant scattering
We performedsoft X-ray resonantscattering experiments on poly (3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-buteric acid methyl ester (PCBM) blend thin films to reveal the domain structure and electronic state, where P3HT and PCBM mean regioregular poly (3-hexylthiophene) and [6,6]-phenyl-C61-buteric acid methyl ester, respectively. We measured two films, where chloroform (CF sample) and 1,2-dichlorobenzene (DCB sample) are used assolvents in the fabrication process. There is negligibleX-ray incident angle dependence of theX-ray absorption spectra at the SK-absorption edge in the CF sample, whereas the DCB sample exhibits cle...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: M. Kubota, T. Sakurai, T. Miyadera, H. Nakao, T. Sugita and Y. Yoshida Source Type: research
Opto-electronic characterization of three dimensional topological insulators
We demonstrate that the terahertz/infraredradiation induced photogalvanic effect, which is sensitive to the surface symmetry and scattering details, can be applied to study the high frequency conductivity of thesurface states in (Bi1 −xSbx)2Te3 based three dimensional (3D) topological insulators (TIs). In particular, measuring the polarization dependence of the photogalvanic current and scanning with a micrometre sized beam spot across the sample, provides access to (i) topographical inhomogeneities in the electronicproperties of thesurface states and (ii) the local domain orientation. An important advantage of the propo...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: H. Plank, S. N. Danilov, V. V. Bel'kov, V. A. Shalygin, J. Kampmeier, M. Lanius, G. Mussler, D. Gr ützmacher and S. D. Ganichev Source Type: research
Traveling Lamb wave in elastic metamaterial layer
The propagation of travelingLamb wave in single layer of elasticmetamaterial is investigated in this paper. We first categorized the travelingLamb wave modes inside an elasticmetamaterial layer according to different combinations (positive or negative) of effective medium parameters. Then the impacts of the frequency dependence of effective parameters on dispersion characteristics of travelingLamb wave were studied. Distinct differences could be observed when comparing the travelingLamb wave along an elasticmetamaterial layer with one inside the traditional elastic layer. We further examined in detail the travelingLamb wav...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Haisheng Shu, Lihuan Xu, Xiaona Shi, Lei Zhao and Jie Zhu Source Type: research
Structural and electronic properties of Fe(AlxGa1 –x)3 system
FeGa3 is a well knownintermetallic semiconductor with aband gap, which is induced by d-p hybridization. In this work, we present the results of experimental andtheoretical studies on the effect ofAl substitution in FeGa3, obtained byX-ray diffraction(XRD) study,temperature dependentresistivitymeasurement, roomtemperature M össbauermeasurement, anddensity functional theory based electronic structure calculations. It is observed that up tox = 0.178 in Fe(AlxGa1 –x)3, which is the maximum range studied in this work,Al substitution reduces thelattice parametersa andc, preserving the parent tetragonal P42/mnm crystal str...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Debashis Mondal, C. Kamal, Soma Banik, Ashok Bhakar, Ajay Kak, Gangadhar Das, V. R. Reddy, Aparna Chakrabarti and Tapas Ganguli Source Type: research
Enhanced absorption of microwave radiations through flexible polyvinyl alcohol-carbon black/barium hexaferrite composite films
Flexiblemicrowave absorbercompositefilms ofcarbon black (CB)/barium hexaferrite nano-discs (BaF) in polyvinyl alcohol (PVA) matrix, fabricated by gel casting, exhibit ∼99.5% attenuation of electromagnetic waves in the entire 8–18 GHz (X and Ku-band) range. The X-ray diffraction and Raman spectroscopy studies confirm the formation of CB-BaF-PVAcompositefilms. The electromagnetic absorption properties ofcompositefilms are found to be enhanced with CB content due to the synergetic effect of multipledielectric and magnetic losses. The 25 wt. % CB grafted PVA-BaF flexiblecompositefilms with a thickness of∼ 2 mm exh...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Sushil Kumar, Gopal Datt, A. Santhosh Kumar and A. C. Abhyankar Source Type: research
Extracting the temperature distribution on a phase-change memory cell during crystallization
Phase-change memory (PCM) devices are enabled by amorphization- and crystallization-induced changes in the devices' electricalresistances. Amorphization is achieved bymelting and quenching the active volume using short duration electrical pulses ( ∼ns). Thecrystallization (set) pulse duration, however, is much longer and depends on the cell temperature reached during the pulse. Hence, the temperature-dependentcrystallization process of the phase-change materials at the device level has to be well characterized to achieve fast PCM operations. A main challenge is determining the cell temperature duringcrystallization. Here...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Gokhan Bakan, Burak Gerislioglu, Faruk Dirisaglik, Zoila Jurado, Lindsay Sullivan, Aykutlu Dana, Chung Lam, Ali Gokirmak and Helena Silva Source Type: research
Coulomb-blockade peak spacing statistics of graphene quantum dots on SiO2
In this report we present the fabrication of lithographically definedquantum dots on SiO2 with short and narrow constrictions and different central island sizes. Low temperature transport measurements display distinctCoulomb-blockade peaks with amplitudes exceeding what is commonly observed experimentally. The analysis of the normalizedCoulomb-blockade peak spacing shows a size dependence, which has not previously been observed fordevices on SiO2. Furthermore, a quantitative comparison of the peak spacing distribution to the literature shows that one of the twodevices compares favorably to a similar sizeddot placed on hexa...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: O. Herrmann, C. Gould and L. W. Molenkamp Source Type: research
Observation of x-ray radiation pressure effects on nanocrystals
We report that this phenomenon can be attributed tox-ray momentum transfer, also known as radiation pressure, to thenanocrystals. Understanding thiseffect is crucial given the anticipated coherent flux increases at next-generation synchrotron sources. (Source: Journal of Applied Physics)
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: J. W. Kim, A. Ulvestad, S. Manna, R. Harder, E. Fohtung, A. Singer, L. Boucheron, E. E. Fullerton and O. G. Shpyrko Source Type: research
Steady state and time resolved optical characterization studies of Zn2SnO4 nanowires for solar cell applications
Nanowires are a promising option for sensitizedsolar cells, sensors, and display technology. Most of the work thus far has focused on binary oxides for thesenanowires, but ternary oxides have advantages in additional control of optical and electronic properties. Here, we report on the diffuse reflectance, Low Temperature and Room TemperaturePhotoluminescence(PL),PL excitationspectrum, andTime ResolvedPL(TRPL) of Zinc Tin Oxide (ZTO)nanowires grown by Chemical Vapor Deposition. ThePL from the ZTOnanowires does not exhibit anyband gap or near gap emission, and the diffuse reflectance measurement confirms that these ZTOnanowi...
Source: Journal of Applied Physics - October 25, 2016 Category: Physics Authors: Baichhabi R. Yakami, Uma Poudyal, Shashank R. Nandyala, Gaurab Rimal, Jason K. Cooper, Xuejie Zhang, Jing Wang, Wenyong Wang and Jon M. Pikal Source Type: research
Wide band gap carbon allotropes: Inspired by zeolite-nets
Based on thetopologies proposed forzeolites, six metastable semiconductorcarbon allotropes withband gaps of 2.72 –3.89 eV are predicted usingab initio density functional calculations. Thehardnesses of these allotropes are about 90% –94% that ofdiamond, indicating that they may be superhard materials. We also present simulatedX-ray diffraction spectra of these newcarbon allotropes to provide a basis for possible experimental observations and synthesis. These newcarbonstructures with a range ofband gaps and withhardnesses comparable todiamond could be potential targets for the synthesis of hard and transparent material...
Source: Journal of Applied Physics - October 24, 2016 Category: Physics Authors: Zhi-Jing Wei, Hui-Yan Zhao, Jing Wang and Ying Liu Source Type: research
An analysis of DSSC performance based on nanosphere, nanorod, and nanoparticle anode morphologies
This study compares thecharge transfer dynamics at the oxide-dye-electrolyte interface inDSSCanodes composed of eithernanoparticles (NPs),nanospheres (NSs), ornanorods (NRs). The crystallinity, morphology, visible light and dyeabsorption on the films were studied byXRD, SEM, and UV-Vis diffuse reflectancespectroscopy while the optoelectronic properties in theDSSC were evaluated by current –voltage, Incident photon to current conversion efficiency, and Electrochemical ImpedanceSpectroscopy (EIS) measurements. Visible lightabsorption was highest in NR films while NS films showed the highest light scattering. However, theDS...
Source: Journal of Applied Physics - October 24, 2016 Category: Physics Authors: Rajour Tanyi Ako, Piyasiri Ekanayake and Chee Ming Lim Source Type: research
