scholarly journals Microstructural Study of CMR Films as a Function of Growth Temperature, As-Deposited and Annealed

1995 ◽  
Vol 401 ◽  
Author(s):  
M. E. Hawley ◽  
X. D. Wu ◽  
P. N. Arendt ◽  
C. D. Adams ◽  
M. F. Hundley ◽  
...  
Keyword(s):  
Data Storage ◽  
Growth Temperature ◽  
Magnetic Data ◽  
Storage Devices ◽  
Colossal Magnetoresistive ◽  
Step Flow ◽  
Transmission Electron ◽  
The Family ◽  
Complex Metal Oxides ◽  
Potential Applications

AbstractThe properties encompassed by the family of complex metal oxides span the spectrum from superconductors to insulating ferroelectrics. Included in this family are the new colossal magnetoresistive perovskites with potential applications in advanced high density magnetic data storage devices based on single or multilayer thin films units of these materials fabricated by vapor phase deposition (PVD) methods. The realization of this potential requires solving basic thin film materials problems requiring understanding and controlling the growth of these materials. Toward this end, we have grown La0.7Ca0.3MnO3 and La0.7Sr0.3MnO3 on LaAlO3 single crystal substrates by pulsed laser and RF sputter deposition at temperatures from 500° C to 900° C and annealed at over 900° C for about 10 hours. The evolution of the microstructure of these films was studied by scanning probe microscopies and transmission electron microscopy (TEM).The results of SPM characterization showed that at the lower end of the growth temperature range, the as-grown films were polygranular with grain size increasing with temperature. The 500° C as-grown films appeared to be amorphous while the 750° C film grains were layered with terrace steps often one unit cell high. In contrast, films grown at 900° C consisted of coalesced islands with some 3-D surface crystals. After annealing, all films had coalesced into very large extended layered islands. The change in microstructure was reflected in a decreased resistivity of coalesced films over their unannealed granular precursors. Previous reported work on the growth of La0.84 Sr0.16MnO3 and La0.8Sr0 2CoO3 grown demonstrated the sensitivity of the microstructure to substrate and deposition conditions. Films grown on an “accidental” vicinal surface grew by a step flow mechanism.

scholarly journals DATA STORAGE: REVIEW OF HEUSLER COMPOUNDS

SPIN ◽  
2012 ◽  
Vol 02 (04) ◽  
pp. 1230006 ◽  
Author(s):  
ZHAOQIANG BAI ◽  
LEI SHEN ◽  
GUCHANG HAN ◽  
YUAN PING FENG
Keyword(s):  
Data Storage ◽  
Giant Magnetoresistance ◽  
Functional Materials ◽  
Recent Decade ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Magnetic Data ◽  
Heusler Compounds ◽  
Storage Devices ◽  
The Family

In the recent decade, the family of Heusler compounds has attracted tremendous scientific and technological interest in the field of spintronics. This is essentially due to their exceptional magnetic properties, which qualify them as promising functional materials in various data-storage devices, such as giant-magnetoresistance spin valves, magnetic tunnel junctions, and spin-transfer torque devices. In this article, we provide a comprehensive review on the applications of the Heusler family in magnetic data storage. In addition to their important roles in the performance improvement of these devices, we also try to point out the challenges as well as possible solutions, of the current Heusler-based devices. We hope that this review would spark further investigation efforts into efficient incorporation of this eminent family of materials into data storage applications by fully arousing their intrinsic potential.

scholarly journals Nanostructured ZnFe2O4: An Exotic Energy Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1286
Author(s):  
Murtaza Bohra ◽  
Vidya Alman ◽  
Rémi Arras
Keyword(s):  
Data Storage ◽  
Smart Materials ◽  
Energy Demand ◽  
Ceramic Materials ◽  
Magnetic Data ◽  
Processing Route ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Reduced Toxicity ◽  
Cation Arrangement

More people, more cities; the energy demand increases in consequence and much of that will rely on next-generation smart materials. Zn-ferrites (ZnFe2O4) are nonconventional ceramic materials on account of their unique properties, such as chemical and thermal stability and the reduced toxicity of Zn over other metals. Furthermore, the remarkable cation inversion behavior in nanostructured ZnFe2O4 extensively cast-off in the high-density magnetic data storage, 5G mobile communication, energy storage devices like Li-ion batteries, supercapacitors, and water splitting for hydrogen production, among others. Here, we review how aforesaid properties can be easily tuned in various ZnFe2O4 nanostructures depending on the choice, amount, and oxidation state of metal ions, the specific features of cation arrangement in the crystal lattice and the processing route used for the fabrication.

scholarly journals GeTe-filled Carbon Nanotubes for Data Storage Applications

2010 ◽  
Vol 1251 ◽  
Author(s):  
Cristina E. Giusca ◽  
Vlad Stolojan ◽  
Jeremy Sloan ◽  
Hidetsugu Shiozawa ◽  
Ravi Silva
Keyword(s):  
Carbon Nanotubes ◽  
Data Storage ◽  
Photoelectron Spectroscopy ◽  
Memory Storage ◽  
Filling Material ◽  
Structural Investigations ◽  
Storage Devices ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

AbstractBy virtue of their unique electronic properties, nanometer-diameter sized single-walled carbon nanotubes represent ideal candidates to function as active parts of nanoelectronic memory storage devices. We show for the first time that GeTe, a phase change material, currently considered to be one of the most promising materials for data-storage applications, can efficiently be encapsulated within single-walled carbon nanontubes of 1.4 nm diameter. Structural investigations on the encapsulated GeTe nanowires have been carried out by high resolution transmission electron microscopy. The electronic interactions between the filling material and the host nanotube have been examined using ultraviolet photoelectron spectroscopy experiments and show that the electronic structure of the encapsulating nanotube and that of the encased filling are not perturbed by the presence of each of the other component.The newly formed hybrids offer potential to operate as active elements in non-volatile electronic memory storage devices.

Synthesis of Passivated Metal Nanoparticles

1999 ◽  
Vol 581 ◽  
Author(s):  
Mark Green ◽  
Paul O'Brien
Keyword(s):  
Thin Films ◽  
Metal Nanoparticles ◽  
Data Storage ◽  
Potential Application ◽  
Lewis Base ◽  
Magnetic Data ◽  
Storage Devices ◽  
Nanoparticle Morphology ◽  
2D And 3D ◽  
Passivated Metal

ABSTRACTHere we report the synthesis of organically passivated nanoparticles of gold, chromium and nickel. The routes involve the reduction of a metal precursor in various Lewis base solvents, which appear to affect the final nanoparticle morphology. The preparation of highly monodispersed samples can lead to the potential for further manipulation of dots into ordered 2D and 3D arrays. These colloidal thin films and crystals have potential application in magnetic data storage devices.

A Novel Apparatus for the Synthesis of Graphite Encapsulated Metallic Nanocrystals

1999 ◽  
Vol 577 ◽  
Author(s):  
K.L. Klug ◽  
D.L. Johnson ◽  
V.P. Dravid
Keyword(s):  
Data Storage ◽  
Chemical Vapor ◽  
Electric Arc ◽  
Raw Material ◽  
Magnetic Data ◽  
Metal Nanocrystals ◽  
New Class ◽  
Potential Applications ◽  
New Apparatus ◽  
Encapsulated Nanoparticles

ABSTRACTGraphite encapsulated metal nanocrystals (GEM nanocrystals) are a promising new class of materials with both scientific and industrial significance. Several encapsulating graphite layers protect the nanoscale metallic core without compromising the inherent magnetic properties of the metal, thereby enhancing studies of small particle magnetism. The size and single domain nature of these particles immediately suggest a wide variety of potential applications ranging from increased density magnetic data storage to immunoassays. Encapsulated nanoparticles have traditionally been synthesized by evaporating a composite metal/graphite anode via an electric arc. While effective, that method also results in a great deal of unwanted amorphous carbon debris in the product. Based on past synthesis runs and observations, an improved apparatus for GEM production has been designed with the goals of increasing GEM yield and reducing soot production. The four segment system consists of I ) a chamber capable of arc or resistive evaporation of raw material(s), 2) a tube furnace for the chemical vapor deposition of carbon on raw material(s) via hydrocarbon dissociation, 3) an increased-efficiency powder collection unit, and 4) a final powder reservoir. Details of the new apparatus are presented here.

A high bandwidth piezoelectric suspension for high track density magnetic data storage devices

1998 ◽  
Vol 34 (4) ◽  
pp. 1907-1909 ◽  
Author(s):  
Wei Guo ◽  
Zhihong Wang ◽  
Xi Yao ◽  
T. Huang ◽  
Chao Bi
Keyword(s):  
Data Storage ◽  
Magnetic Data Storage ◽  
Track Density ◽  
Magnetic Data ◽  
Storage Devices ◽  
High Bandwidth ◽  
High Track

HR-TEM Studies of FePt Nanoparticles by Exit Wave Reconstruction

2007 ◽  
Vol 998 ◽  
Author(s):  
Daniela Sudfeld ◽  
Olga Dmitrieva ◽  
Nina Friedenberger ◽  
Guenter Dumpich ◽  
Michael Farle ◽  
...  
Keyword(s):  
Data Storage ◽  
Density Functional ◽  
Lattice Structure ◽  
Magnetic Behavior ◽  
Magnetic Data ◽  
Fept Nanoparticles ◽  
Face Centered Cubic ◽  
Scattered Electron ◽  
Transmission Electron ◽  
Face Centered

ABSTRACTFePt nanoparticles are promising materials for high-density magnetic data storage media [1] and bio-medical applications such as drug-targeting and hyperthermia [2]. To understand their magnetic properties [3] it is essential to get insights into the lattice structure of isolated nanoparticles which influence the magnetic behavior.Typically, lattice fringes are observed with high-resolution transmission electron microscopy (HR-TEM). In this case delocalization effects disturb imaging of the lattice structure in particular if 2 to 6 nm small nanoparticles are involved. Therefore, FePt nanocrystals were investigated by reconstructing amplitude and phase of the scattered electron wave from a focal series of HRTEM images, which can produce delocalization free and direct images of the crystal structure [4]. The formation of 5-fold twinned structures of 3 to 7 nm face-centered cubic FePt nanocrystals is investigated that were grown from a colloidal solution [1]. The results are compared with abinitio density functional (DFT) calculations of FePt particles with a diameter of larger than 2 nm. Image simulations were performed with the Accelrys Cerius2 software package (Version 4.6). Good agreement between the ab-initio calculations and the experimental data is found.

scholarly journals Effect of Time on a Hierarchical Corn Skeleton-Like Composite of CoO@ZnO as Capability Electrode Material for High Specific Performance Supercapacitors

2018 ◽  
Author(s):  
Anil Kumar Yedluri ◽  
Hee-Je Kim
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Energy Storage Devices ◽  
X Ray ◽  
Storage Devices ◽  
Transmission Electron ◽  
Potential Applications ◽  
Oxygen Groups ◽  
Cbd Method

CoO-ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the CBD method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, low and high-resolution of scanning electron microscopy, and transmission electron microscopy. The as-synthesized hierarchical nanocorn skeleton-like structure of CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance of 1136 F/g at a current density of 3 A/g with outstanding cycling stability, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO (CO), ZnO (ZO), CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274, 383, 240 and 537 F/g, respectively). This superior capacitance was attributed to the ideal surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.

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