Magnetic property under the pressure and electrical transport behavior under the magnetic field for the perovskite manganite La0.7Ca0.3MnO3

2020 ◽  
Vol 837 ◽  
pp. 155476 ◽  
Author(s):  
R. Rao ◽  
Y.Y. Han ◽  
X.C. Kan ◽  
X. Zhang ◽  
M. Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Property ◽  
Electrical Transport ◽  
Perovskite Manganite ◽  
Transport Behavior ◽  
The Magnetic Field

scholarly journals A distinct magnetic property of the inner penumbral boundary

2020 ◽  
Vol 638 ◽  
pp. A28 ◽  
Author(s):  
Jan Jurčák ◽  
Markus Schmassmann ◽  
Matthias Rempel ◽  
Nazaret Bello González ◽  
Rolf Schlichenmaier
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Potential Field ◽  
Magnetic Energy ◽  
Vertical Component ◽  
Flux Rope ◽  
Field Configuration ◽  
The Magnetic Field ◽  
Upper Boundary

Context. Analyses of sunspot observations revealed a fundamental magnetic property of the umbral boundary: the invariance of the vertical component of the magnetic field. Aims. We analyse the magnetic properties of the umbra-penumbra boundary in simulated sunspots and thus assess their similarity to observed sunspots. We also aim to investigate the role of the plasma β and the ratio of kinetic to magnetic energy in simulated sunspots in the convective motions because these quantities cannot be reliably determined from observations. Methods. We used a set of non-gray simulation runs of sunspots with the MURaM code. The setups differed in terms of subsurface magnetic field structure and magnetic field boundary imposed at the top of the simulation domain. These data were used to synthesize the Stokes profiles, which were then degraded to the Hinode spectropolarimeter-like observations. Then, the data were treated like real Hinode observations of a sunspot, and magnetic properties at the umbral boundaries were determined. Results. Simulations with potential field extrapolation produce a realistic magnetic field configuration on the umbral boundaries of the sunspots. Two simulations with a potential field upper boundary, but different subsurface magnetic field structures, differ significantly in the extent of their penumbrae. Increasing the penumbra width by forcing more horizontal magnetic fields at the upper boundary results in magnetic properties that are not consistent with observations. This implies that the size of the penumbra is given by the subsurface structure of the magnetic field, that is, by the depth and inclination of the magnetopause, which is shaped by the expansion of the sunspot flux rope with height. None of the sunspot simulations is consistent with the observed properties of the magnetic field and the direction of the Evershed flow at the same time. Strong outward-directed Evershed flows are only found in setups with an artificially enhanced horizontal component of the magnetic field at the top boundary that are not consistent with the observed magnetic field properties at the umbra-penumbra boundary. We stress that the photospheric boundary of simulated sunspots is defined by a magnetic field strength of equipartition field value.

Nanosize effects on the magnetic field induced transitions in La0.67−xEuxCa0.33MnO3 perovskite manganite

2014 ◽  
Vol 368 ◽  
pp. 308-311 ◽  
Author(s):  
N. Raju ◽  
D. Roja Sree ◽  
S. Shravan Kumar Reddy ◽  
Ch. Gopal Reddy ◽  
P. Yadagiri Reddy ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Perovskite Manganite ◽  
The Magnetic Field

MAGNETIC PROPERTY AND CRITICAL CURRENT OF BiSrCaCuO SYSTEM UNDER LOW MAGNETIC FIELD

1989 ◽  
Vol 03 (06) ◽  
pp. 505-508
Author(s):  
L.Z. CAO ◽  
Y. YUE ◽  
J. WANG ◽  
S.D. MAO ◽  
H.B. LIU ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Property ◽  
Critical Current ◽  
Critical Field ◽  
Current Density ◽  
Pinning Force ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field ◽  
Low Magnetic Field ◽  
The Magnetic Field

The low critical field H c1 is determined by a.c.χ versus H and M versus H. For a sample of BiSrCaCuO with T c (0)=89 K , H c1 is equal to 17.5 Oe at 77 K. Measurement of the critical current Jc under low magnetic field shows that there is a peak on J c -H curve at about 1 Oe due to the existence of the earth’s magnetic field and the current density is very small in the BiSrCaCuO system and J c is nearly zero when the magnetic field reaches 150 Oe. It is suggested that the pinning force is very weak in this material.

Positive magnetoresistance of La0.7Sr0.3MnO3/C composites

2016 ◽  
Vol 09 (05) ◽  
pp. 1650054
Author(s):  
Yu. V. Kabirov ◽  
V. G. Gavrilyachenko ◽  
A. S. Bogatin
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Linear Dependence ◽  
Room Temperature ◽  
Perovskite Manganite ◽  
Positive Magnetoresistance ◽  
The Magnetic Field

The perovskite manganite La[Formula: see text]Sr[Formula: see text]MnO3 compound is used as a component in ceramic ([Formula: see text](La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-xC composites at x = 0.15–0.85. It is found that every studied specimen is characterized by the linear dependence of the positive magnetoresistance (PMR) on the magnetic field strength at room temperature. The 0.6(La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-0.4C composite has the largest magnetoresistance value (15%) at room temperature and intensity of magnetic field [Formula: see text][Formula: see text]kOe. A possible mechanism for the PMR of ([Formula: see text](La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-xC composites is discussed.

scholarly journals Magnetotransport studies of Fe vacancy-ordered Fe4+δSe5nanowires

2020 ◽  
Vol 117 (23) ◽  
pp. 12606-12610
Author(s):  
Keng-Yu Yeh ◽  
Tung-Sheng Lo ◽  
Phillip M. Wu ◽  
Kuei-Shu Chang-Liao ◽  
Ming-Jye Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electrical Transport ◽  
Parent Phase ◽  
Mixed Valence ◽  
Field Orientation ◽  
Spin Orbital ◽  
Field Independent ◽  
Mi Transition ◽  
The Magnetic Field

We studied the electrical transport of Fe4+δSe5single-crystal nanowires exhibiting √5 × √5 Fe-vacancy order and mixed valence of Fe. Fe4+δSe5compound has been identified as the parent phase of FeSe superconductor. A first-order metal-insulator (MI) transition of transition temperatureTMI∼ 28 K is observed at zero magnetic fields (B). Colossal positive magnetoresistance emerges, resulting from the magnetic field-dependent MI transition.TMIdemonstrates anisotropic magnetic field dependence with the preferred orientation along thecaxis. At temperatureT< ∼17 K, the state of near-magnetic field-independent resistance, which is due to spin polarized even at zero fields, preserves under magnetic fields up toB= 9 T. The Arrhenius law shift of the transition on the source-drain frequency dependence reveals that it is a nonoxide compound with the Verwey-like electronic correlation. The observation of the magnetic field-independent magnetoresistance at low temperature suggests it is in a charge-ordered state belowT∼ 17 K. The results of the field orientation measurements indicate that the spin-orbital coupling is crucial in √5 × √5 Fe vacancy-ordered Fe4+δSe5at low temperatures. Our findings provide valuable information to better understand the orbital nature and the interplay between the MI transition and superconductivity in FeSe-based materials.

Vector magnetic property of electrical steel sheet and its influence on distributions of magnetic field and iron loss for electrical machines

2013 ◽  
Vol 33 (1/2) ◽  
pp. 14-27 ◽  
Author(s):  
Heesung Yoon ◽  
Chang Seop Koh
Keyword(s):  
Magnetic Field ◽  
Magnetic Property ◽  
Steel Sheet ◽  
Electrical Steel ◽  
Electrical Machines ◽  
Iron Loss ◽  
Element Analysis ◽  
Content Type ◽  
Electrical Steel Sheet ◽  
The Magnetic Field

Purpose – The purpose of this paper is to present the vector magnetic properties of the electrical steel sheet and investigate its influences on the magnetic field and iron loss distributions for the electrical machines. Design/methodology/approach – The vector magnetic property of the electrical steel sheet is measured by using a two-dimensional single sheet tester and modelled through an E&S vector hysteresis model to be applied to finite element analysis. Findings – The magnetic field and iron loss distributions are calculated by finite element analysis combined with the E&S vector hysteresis model for the three-phase transformer and induction motor models. Originality/value – The influences of the vector magnetic property on the electrical machines are verified by comparing with the numerical results from a scalar magnetic property.

Competition Between Anti-Phase Boundaries and Charge-Orbital Ordering in Epitaxial Stepped Fe3O4(100) Thin Films

SPIN ◽  
2016 ◽  
Vol 07 (02) ◽  
pp. 1750001 ◽  
Author(s):  
Han-Chun Wu ◽  
Xiao Liu ◽  
Cormac Ó. Coileáin ◽  
Hongjun Xu ◽  
Mourad Abid ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Transport Properties ◽  
Electrical Transport ◽  
Anisotropy Constant ◽  
Electrical Contacts ◽  
Orbital Ordering ◽  
Electrical Transport Properties ◽  
Phase Boundaries ◽  
The Magnetic Field

Magnetite is a highly utilized transition metal oxide with many interesting magnetic and transport properties. The presence of anti-phase boundaries (APBs) and charge-orbital ordering (COO) are two of the most exciting properties of epitaxial magnetite thin films. Here, epitaxial stepped Fe3O4 films were prepared to investigate the competition between APBs and COO via measurements of in-plane anisotropy. The anisotropy was probed for two orthogonal configurations, with magnetic field applied or electrical-contacts aligned either along or perpendicular to the steps. We reveal that the APBs dominate the magnetic and transport properties of the films above the Verwey transition temperature ([Formula: see text]. However, below [Formula: see text] film thickness becomes a decisive factor in determining the magnetic nature of stepped magnetite films, due to its correlation with domain size. When the film is thinner than a critical thickness, the anisotropy is dominated by the APBs, and a higher anisotropy constant and MR ratio are observed when the magnetic field or contacts are oriented along the steps. Conversely, for sufficiently thick films, below [Formula: see text], the magnetic and electrical transport properties are dominated by COO. Thus a higher anisotropy constant and MR ratio are observed when the magnetic field or contacts are oriented perpendicular to the steps.

Sign in / Sign up

Export Citation Format

Share Document