Room-Temperature Ferromagnetism in (III,Mn)Sb Semiconductors

2012 ◽  
Vol 190 ◽  
pp. 109-112
Author(s):  
Y.A. Danilov ◽  
B.N. Zvonkov ◽  
Alexei V. Kudrin ◽  
O.V. Vikhrova ◽  
S.M. Plankina ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Kerr Effect ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Laser Deposition ◽  
Ferromagnetic Semiconductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaseous Environment

t is reported about fabrication by laser deposition in a gaseous environment of epitaxial layers of ferromagnetic semiconductors GaMnSb and InMnSb. Investigations of x-ray diffraction and Raman scattering showed reasonably good crystal quality of GaMnSb and InMnSb layers. Magnetic properties were investigated by magneto-optical transversal Kerr effect and Hall effect. It is established, that GaMnSb layers are ferromagnetic at room temperature. In contrast, InMnSb samples demonstrate the ferromagnetic properties only at low temperatures (< 70 K).

Magnetic Properties of Sputtered Fe-O and Co-O Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
D. V. Dimitrov ◽  
A. S. Murthy ◽  
G. C. Hadjipanayis ◽  
C. P. SWANN
Keyword(s):  
Grain Size ◽  
Low Temperatures ◽  
Room Temperature ◽  
Oxide Films ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Large Shift ◽  
X Ray ◽  
Grain Size And Shape ◽  
Spherical Grains

AbstractFe-O and Co-O films were prepared by DC magnetron sputtering in a mixture of Ar and O2 gases. By varying the oxygen to argon ratio, oxide films with stoichiometry FeO, Fe3O4, α-Fe2O3, CoO and Co3O4 were produced. TEM studies showed that the Fe – oxide films were polycrystalline consisting of small almost spherical grains, about 10 nm in size. Co-O films had different microstructure with grain size and shape dependent on the amount of oxygen. X-ray diffraction studies showed that the grains in Fe-O films were randomly oriented in contrast to Co-O films in which a <111> texture was observed. Pure FeO and α-Fe2O3 films were found to be superparamagnetic at room temperature but strongly ferromagnetic at low temperatures in contrast to the antiferromagnetic nature of bulk samples. A very large shift in the hysteresis loop, about 3800 Oe, was observed in field cooled Co-CoO films indicating the presence of a large unidirectional exchange anisotropy.

Long-term Room Temperature Instability in Thermal Conductivity of InGaZnO Thin Films

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Storage Time ◽  
Laser Deposition ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
3Ω Method ◽  
X Ray

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.

scholarly journals An operando X-ray diffraction study of chloroaluminate anion-graphite intercalation in aluminum batteries

2018 ◽  
Vol 115 (22) ◽  
pp. 5670-5675 ◽  
Author(s):  
Chun-Jern Pan ◽  
Chunze Yuan ◽  
Guanzhou Zhu ◽  
Qian Zhang ◽  
Chen-Jui Huang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Negative Electrode ◽  
Discharge Voltage ◽  
Battery Life ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stage 4 ◽  
Graphite Intercalation ◽  
Battery Discharge

We investigated rechargeable aluminum (Al) batteries composed of an Al negative electrode, a graphite positive electrode, and an ionic liquid (IL) electrolyte at temperatures down to −40 °C. The reversible battery discharge capacity at low temperatures could be superior to that at room temperature. In situ/operando electrochemical and synchrotron X-ray diffraction experiments combined with theoretical modeling revealed stable AlCl4−/graphite intercalation up to stage 3 at low temperatures, whereas intercalation was reversible up to stage 4 at room temperature (RT). The higher-degree anion/graphite intercalation at low temperatures affords rechargeable Al battery with higher discharge voltage (up to 2.5 V, a record for Al battery) and energy density. A remarkable cycle life of >20,000 cycles at a rate of 6C (10 minutes charge time) was achievable for Al battery operating at low temperatures, corresponding to a >50-year battery life if charged/discharged once daily.

Hydrothermal Synthesis and Room Temperature Ferromagnetism of Ni-Doped Rod-Like ZnO Particles

2014 ◽  
Vol 934 ◽  
pp. 71-74
Author(s):  
Lian Mao Hang ◽  
Zhao Ji Zhang ◽  
Zhi Yong Zhang
Keyword(s):  
Quantum Interference ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Hexagonal Wurtzite Structure ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Particles

Ni-doped rod-like ZnO particles with doping concentration of 1 at.% were synthesized at 200°C by hydrothermal method and characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and superconducting quantum interference device (SQUID). The results show that the as-synthesized samples are pure hexagonal wurtzite structure without metallic Ni or other secondary phases and display rod-like shape with smooth surface. The magnetization measurements reveal that the Ni-doped rod-like ZnO particles show ferromagnetic behavior at room temperature. The saturation magnetization and coercive field are 0.0046 emu/g and 15 Oe, respectively.

scholarly journals Lead potassium niobate thin films grown by Pulsed Laser Deposition

2016 ◽  
Vol vol1 (1) ◽  
Author(s):  
Billal Allouche ◽  
Yaovi Gagou ◽  
M. El Marssi
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Potassium Niobate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Deposition Parameters ◽  
Out Of Plane

By pulsed laser deposition, lead potassium niobate Pb2KNb5O15 was grown on (001) oriented Gd3Ga5O12 substrate using a platinum buffer layer. The PKN thin films were characterized by X-Ray diffraction and Scanning Electron Microscopy (SEM). The dependence of their structural properties as a function of the deposition parameters was studied. It has been found that the out of plane orientation of PKN film depends on the oxygen pressure used during the growth. Indeed, PKN thin film is oriented [001] for low pressure and is oriented [530] for high pressure. For these two orientations, the crystalline quality of PKN film was determined using omega scans.

scholarly journals Structure Quality of LuFeO3 Epitaxial Layers Grown by Pulsed-Laser Deposition on Sapphire/Pt

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 61 ◽  
Author(s):  
Sondes Bauer ◽  
Adriana Rodrigues ◽  
Lukáš Horák ◽  
Xiaowei Jin ◽  
Reinhard Schneider ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Lattice Parameter ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray

Structural quality of LuFeO 3 epitaxial layers grown by pulsed-laser deposition on sapphire substrates with and without platinum Pt interlayers has been investigated by in situ high-resolution X-ray diffraction (reciprocal-space mapping). The parameters of the structure such as size and misorientation of mosaic blocks have been determined as functions of the thickness of LuFeO 3 during growth and for different thicknesses of platinum interlayers up to 40 nm. By means of fitting of the time-resolved X-ray reflectivity curves and by in situ X-ray diffraction measurement, we demonstrate that the LuFeO 3 growth rate as well as the out-of-plane lattice parameter are almost independent from Pt interlayer thickness, while the in-plane LuFeO 3 lattice parameter decreases. We reveal that, despite the different morphologies of the Pt interlayers with different thickness, LuFeO 3 was growing as a continuous mosaic layer and the misorientation of the mosaic blocks decreases with increasing Pt thickness. The X-ray diffraction results combined with ex situ scanning electron microscopy and high-resolution transmission electron microscopy demonstrate that the Pt interlayer significantly improves the structure of LuFeO 3 by reducing the misfit of the LuFeO 3 lattice with respect to the material underneath.

MBE GROWN ZnSSe/ZnMgSSe MQW STRUCTURE FOR BLUE VCSEL

2007 ◽  
Vol 06 (05) ◽  
pp. 407-410 ◽  
Author(s):  
I. P. KAZAKOV ◽  
V. I. KOZLOVSKY ◽  
V. P. MARTOVITSKY ◽  
YA. K. SKASYRSKY ◽  
M. D. TIBERI ◽  
...  
Keyword(s):  
Room Temperature ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Optical Scanning ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Two Phases

ZnSSe / ZnMgSSe MQW structures were grown by molecular beam epitaxy on GaAs substrates. The band gap of ZnMgSSe barriers was approximately 3 eV at room temperature. Cathodoluminescence, X-ray diffraction, optical, scanning electron beam, and atomic force microscopy were all used for structure characterization. Decay of the ZnMgSSe solid solution in at least two phases was observed. Improvement in the quality of the crystal lattice and surface morphology was achieved by mismatching the ZnMgSSe from the GaAs substrate by increasing the lattice period by 0.24%.

Room Temperature Ferromagnetism in Powder Form of Sn1-xCrxO2 (x = 0.01, 0.02, 0.03, 0.04 and 0.05) Solid Solution

2009 ◽  
Vol 1201 ◽  
Author(s):  
Kun Xu ◽  
Mitsuru Izumi ◽  
Osami Yanagisawa ◽  
Tetsuya Ida
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Lattice Parameter ◽  
Nominal Composition ◽  
Powder Form ◽  
X Ray Diffraction ◽  
Interstitial Position ◽  
X Ray ◽  
Cr Content ◽  
Structural And Magnetic Properties

AbstractStructural and magnetic properties were investigated in the mixed powders of Sn1-xCrxO2 (x = 0.01, 0.02, 0.03, 0.04 and 0.05) in nominal composition. The lattice parameter observed in (110) x-ray diffraction indicates two step changes with increasing Cr content. The occupation of Cr ion at the interstitial position leads to elongation of the lattice parameter for x = 0.01 to x =0.03. Then, the Cr3+ ions are remarkably substituted into the Sn4+ ion site for x = 0.04 to x = 0.05, which results in shortening of the lattice. The lattice parameters for x = 0.01 and 0.02 are larger than x = 0.03 to 0.05. The room temperature ferromagnetism appeared in the sample with x = 0.01 and reaches maximum at the doping rate of x = 0.02; while the magnetization decreases for x > 0.02 was observed. Present study clearly shows the existence of correlation between appearance of ferromagnetism and the structural change.

Strontium Barium Niobate Thin Films Prepared by Pulsed Laser Deposition

1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Liu ◽  
C.W. Ong ◽  
P.W. Chan ◽  
C.L. Choy
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Crystallite Orientation ◽  
Strontium Barium ◽  
Film Composition ◽  
X Ray

ABSTRACTStrontium barium niobate Sr0.55Ba0.45Nb2O6 thin films were prepared on Si (111) substrates by pulsed laser deposition (PLD). The film composition was determined as a function of the fluence φ and wavelength λ of the laser beam, the oxygen ambient pressure Po2 and the substrate temperature Ts. The results show that the film composition is very close to that of the target, and is almost independent of φ from 1 to 8 J cm−2, λ = 355, 532 and 1064 nm, Po2 from 0 to 150 mTorr, and Ts from 25 to 700°C. These results suggest that PLD is excellent for preparing SBN films with compositions congruent to that of the target. The x-ray diffraction data show that all the samples deposited at room temperature are amorphous. The x-ray diffraction results also indicate that the samples deposited at 700°C have a tungsten-bronze-(TB-) type structure with preferred crystallite orientation, while the room-temperature-deposited samples after annealing at 800°C for 30 minutes are polycrystalline and have random crystallite orientation.

Nano Aluminum Powders Oxidation in CO2 and O2 Environments

2013 ◽  
Vol 771 ◽  
pp. 113-117 ◽  
Author(s):  
Hong Bo Pei ◽  
Yang Liu ◽  
Hui Ren
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Oxidation Process ◽  
Oxidation Products ◽  
X Ray Diffraction ◽  
Aluminum Particles ◽  
Aluminum Powders ◽  
X Ray ◽  
Oxidation Processes ◽  
Oxidation Properties

An experimental study of oxidation of nano aluminum (Al) powders in CO2 and O2 is described. The oxidation is studied using thermogravimetric (TG) measurements from room temperature to 1500°C. Partially oxidized samples are recovered and their compositions are analyzed using X-ray diffraction. The oxidation product morphology was examined using SEM. Dimensional properties of aluminum particles have a significant influence on the oxidation processes. The nano aluminum reaction onset temperature was much lower than micro aluminum. Distinctly different oxidation properties of nano aluminum powders were shown between CO2 and O2. nano aluminum powders could ignite in O2 at fairly low temperatures around 530 °C. However ignition for nano aluminum powders in CO2 didn't appeared below 1500 °C. There was a weight loss in the TG curves at around 1200 °C for nano Al-CO2 system. It was thought that small amount of carbon formed in the oxidation process. The XRD showed that both the nano aluminum oxidation products were α-Al2O3 in CO2 and O2.

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