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Nanoscale grains, high irreversibility field and large

2008-2-8  As part of a recent review article, Braccini et al reported on the effect of high-energy ball milling on J c of undoped ex situ tapes. They found that increased (but unspecified) milling time had only a small effect on low-field J c of the heat treated samples, but that the irreversibility field ( H * ) increased from 5.7 to 11 T with tape surface and 8.8 to 12 T with tape surface.

Nanoscale grains, high irreversibility field and large

Milling had a weak detrimental effect on the connectivity. A strong irreversibility field ( H ∗ ) increase (from 13.3 to 17.2 T at 4.2 K) due to increased milling time

Nanoscale grains, high irreversibility field and large

2008-2-8  Milling had a weak detrimental effect on the connectivity. A strong irreversibility field (H*) increase (from 13.3 to 17.2 T at 4.2 K) due to increased milling time was observed and correlated linearly with inverse grain size (1/d). As a result, the high-field Jcbenefited greatly from lengthy powder milling.

Effect of ball milling on the local magnetic flux

2019-5-10  microstructure has been widely searched by mechanical ball-milling of different precursor powders: MgB 2 [9], Mg + B [10-14], B [15-18], or Mg [12], to prepare bulks and wires with the ex situ and in situ reaction methods. By increasing the milling energy transferred to the precursor, the irreversibility

Electrochemical properties of the TiO 2 (B) powders ball

2013-11-6  The irreversibility of 12.4% of as-synthesized sample was also greatly improved to 7% after ball milling treatment. Our results indicate ball mill treatment can be an economical way to improve electrochemical properties of TiO2(B) anode materials for lithium ion battery application.

Nanoscale grains, high irreversibility field, and large

Milling had a weak detrimental effect on connectivity. Strong irreversibility field (H*) increase (from 13.3 T to 17.2 T at 4.2 K) due to increased milling time was observed and correlated linearly with inverse grain size (1/d). As a result, high field Jc benefited greatly from lengthy powder milling.

Effect of ball milling on the local magnetic flux

2017-9-15  Ball-milling the precursor enhances vortex pinning at high magnetic fields, so that the highest J c ′s at 5 K and μ 0 H > 5 T correspond to the conductor made from the highest energy milled precursor. Nevertheless, the use of the precursor with milling energies above a certain limit produces microstructural defects during mechanical deformation, resulting in the formation of large transversal cracks, which

Irreversibility Line an overview ScienceDirect Topics

The irreversibility line can also be obtained by hysteresis loop measurements and I–V characteristics measurements. Generally, the irreversibility line follows 1 − T irr / T c 0 = C H irr q, with T c0 the zero-field transition temperature, and 1 / 2 < q < 3 / 4, depending on different materials.

Superconducting properties of polycrystalline YBa2Cu3O7

2014-1-1  It is demonstrated that ball milling is an effective approach for obtaining fine particles with size about 15 nm gathered into coral-like agglomerates and embedded in the matrix. Such decorated finer structure contributes to the enhancement of the inter-grains and intra-grains critical current density of the material under an applied magnetic field.

High trapped fields in bulk MgB2 prepared by hot

prepared by ball-milling of Mg and B powders followed by hot-pressing, will be presented. 2. Experiments For the preparation of MgB2, magnesium powder (Goodfel-low, purity 99.8%, grain size <250 m) and amorphous boron powder (purity 99%, grain size <1 m) were used. Mechanical alloying was done using a Retsch PM 4000

Transport critical current, anisotropy, irreversibility

2002-3-27  The influence of the initial MgB2 grain size on critical current density, upper critical fields and irreversibility has been studied on Fe sheathed monofilamentary MgB2 tapes prepared by the Powder-In-Tube technique. The effect of the reduction of MgB2 grain size by ball milling was mainly to enhance both the critical current density, jc, and the irreversibility field, while the upper critical

Magnetic irreversibility in ultrafine ZnFe2O4 particles

2016-12-8  High-energy ball milling~HEBM! has been used as an alter-native route to obtain novel materials through solid-state re-actions, since mechanochemical reactions usually yield highly metastable phases. The structure of the spinel oxides AB2O4 consists of a

BALL MILLING IN THE PRESENCE OF A FLUID: RESULTS

2012-2-13  this irreversibility. The explanation is as follows: the surface increase is mainly due to the cleavage of graphite (the mean diameter is divided by a factor of 2 to 10, the thickness by 200 to 500) occuring preferentially at the defects ; thus the ball milling leads to a better crystallinity and can be consid-ered, in this case, really as a

Nanoscale grains, high irreversibility field, and large

Milling had a weak detrimental effect on connectivity. Strong irreversibility field (H*) increase (from 13.3 T to 17.2 T at 4.2 K) due to increased milling time was observed and correlated linearly with inverse grain size (1/d). As a result, high field Jc benefited greatly from lengthy powder milling.

A low-cost and high performance ball-milled Si-based

A Si-based anode with improved performance can be achieved using high-energy ball-milling as a cheap and easy process to produce Si powders prepared from a coarse-grained material. Ball-milled powders present all the advantages of nanometric Si powders, but

Improved superconducting properties in graphene-doped

2020-4-25  MgB2 bulks with graphene doping were synthesized by high energy ball milling process. The effect of high energy ball milling and graphene doping on the microstructure and critical current density of MgB2 was studied systematically. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and physical property

Effect of Ball-Milling on 3-V Capacity of Lithium

2001-4-5  Ball-milling for a sufficient period of time of lithium−manganese oxide spinels, prepared either by a sol−gel method or by solid-state reaction, gave cathode materials of a lithium cell with excellent capacity retention in the 3-V range at room temperature and elevated temperatures despite an apparent Jahn−Teller distortion. In a 50-cycle test with 0.5 mA/cm2, a sample ball-milled for 1

Magnetic properties of ZnFe2O4 synthesized by ball milling

2016-12-8  a planetary ball mill with closed containers of hardened steel, with ball to sample mass ratio 20:1. Acetone was added to improvehomogeneityduring milling. The mill-ing process was stopped after selected intervals of 100, 300, 400 and 623h, to extract small amounts of sample (labeled as Z100, Z300, Z400 and Z623, respectively).

Stoichiometric Irreversibility of Aged Garnet Electrolytes

@article{osti_1773604, title = {Stoichiometric Irreversibility of Aged Garnet Electrolytes}, author = {Cai, Jiyu and Polzin, Bryant and Fan, Longlong and Yin, Liang and Liang, Yujia and Li, Xiang and Liu, Qian and Trask, Steve and Liu, Yuzi and Ren, Yang and Meng, Xiangbo and Chen, Zonghai}, abstractNote = {Solid-state lithium batteries (SSLBs) have been regarded as one of the next-generation

Journal of Alloys and Compounds Hashemite University

2017-1-29  All samples were prepared by ball milling and extracted from the same batch we used in our previous study [22]. The starting materials for synthesis of SrFe12 2xRuxTixO19 with x ¼ 0.0, 0.1, 0.2, and 0.3 were high purity metallic oxides (Fe2O3 99%, TiO 99% and RuO2 99%) and strontium carbonate (SrCO3 99%). The molar ratio of

Magnetic irreversibility in ultrafine ZnFe2O4 particles

2016-12-8  High-energy ball milling~HEBM! has been used as an alter-native route to obtain novel materials through solid-state re-actions, since mechanochemical reactions usually yield highly metastable phases. The structure of the spinel oxides AB2O4 consists of a

Transport critical current, anisotropy, irreversibility

2002-3-27  The influence of the initial MgB2 grain size on critical current density, upper critical fields and irreversibility has been studied on Fe sheathed monofilamentary MgB2 tapes prepared by the Powder-In-Tube technique. The effect of the reduction of MgB2 grain size by ball milling was mainly to enhance both the critical current density, jc, and the irreversibility field, while the upper critical

BALL MILLING IN THE PRESENCE OF A FLUID: RESULTS

2012-2-13  this irreversibility. The explanation is as follows: the surface increase is mainly due to the cleavage of graphite (the mean diameter is divided by a factor of 2 to 10, the thickness by 200 to 500) occuring preferentially at the defects ; thus the ball milling leads to a better crystallinity and can be consid-ered, in this case, really as a

Effect of ball milling on the local magnetic flux

2020-4-28  microstructure has been widely searched by mechanical ball-milling of different precursor powders: MgB 2 [9], Mg + B [10-14], B [15-18], or Mg [12], to prepare bulks and wires with the ex situ and in situ reaction methods. By increasing the milling energy transferred to the precursor, the irreversibility

Magnetic properties of ZnFe2O4 synthesized by ball milling

2016-12-8  a planetary ball mill with closed containers of hardened steel, with ball to sample mass ratio 20:1. Acetone was added to improvehomogeneityduring milling. The mill-ing process was stopped after selected intervals of 100, 300, 400 and 623h, to extract small amounts of sample (labeled as Z100, Z300, Z400 and Z623, respectively).

Effect of Ball-Milling on 3-V Capacity of Lithium

2001-4-5  Ball-milling for a sufficient period of time of lithium−manganese oxide spinels, prepared either by a sol−gel method or by solid-state reaction, gave cathode materials of a lithium cell with excellent capacity retention in the 3-V range at room temperature and elevated temperatures despite an apparent Jahn−Teller distortion. In a 50-cycle test with 0.5 mA/cm2, a sample ball-milled for 1

Stoichiometric Irreversibility of Aged Garnet Electrolytes

@article{osti_1773604, title = {Stoichiometric Irreversibility of Aged Garnet Electrolytes}, author = {Cai, Jiyu and Polzin, Bryant and Fan, Longlong and Yin, Liang and Liang, Yujia and Li, Xiang and Liu, Qian and Trask, Steve and Liu, Yuzi and Ren, Yang and Meng, Xiangbo and Chen, Zonghai}, abstractNote = {Solid-state lithium batteries (SSLBs) have been regarded as one of the next-generation

PREPARATION AND CHARACTERIZATION OF MgB2 BULK

2008-3-4  MgB 2 bulk samples were prepared using high‐energy ball milling in nitrogen atmosphere followed by cold isostatic pressing and hot isostatic pressing to increase densification and grain connectivity. Higher values of critical current densities J c at high magnetic fields could be obtained after milling than those obtained with unmilled bulk samples. J c values around 20,000 A / cm 2 at 7 T

PREPARATION AND CHARACTERIZATION OF MgB2 BULK

2008-3-4  MgB 2 bulk samples were prepared using high‐energy ball milling in nitrogen atmosphere followed by cold isostatic pressing and hot isostatic pressing to increase densification and grain connectivity. Higher values of critical current densities J c at high magnetic fields could be obtained after milling than those obtained with unmilled bulk

Journal of Alloys and Compounds Hashemite University

2017-1-29  All samples were prepared by ball milling and extracted from the same batch we used in our previous study [22]. The starting materials for synthesis of SrFe12 2xRuxTixO19 with x ¼ 0.0, 0.1, 0.2, and 0.3 were high purity metallic oxides (Fe2O3 99%, TiO 99% and RuO2 99%) and strontium carbonate (SrCO3 99%). The molar ratio of