Mössbauer and Magnetic Study of Solid Phases Formed by Dissimilatory Iron-Reducing Bacteria

2012 ◽  
Vol 190 ◽  
pp. 721-724 ◽  
Author(s):  
N.I. Chistyakova ◽  
V.S. Rusakov ◽  
A.A. Shapkin ◽  
P.A. Pigalev ◽  
A.P. Kazakov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Liquid Nitrogen ◽  
Temperature Interval ◽  
Zero Field ◽  
Iron Reducing Bacteria ◽  
Solid Phases ◽  
Reducing Bacteria ◽  
Zero Field Cooling ◽  
Field Cooling

Mössbauer investigations of solid phases that were formed during the reduction of amorphous synthesized ferrihydrite (SF) by thermophilic anaerobic iron-reducing bacterium Thermincola ferriacetica (strain Z-0001) and alkaliphilic anaerobic iron-reducing bacterium Geoalkalibacter ferrihydriticus (strain Z-0531) were carried out at room, liquid nitrogen and helium temperatures in the presence or the absence of an external magnetic field (6 T). The magnetization M (T, H) was measured in the temperature interval 80-300 K and magnetic field up to 10 kOe. It was performed zero field cooling (ZFC) and field cooling (FC) measurements of M (T).

Magnetic Properties of the Gd1-xTbxNi3 Intermetallic Compounds

2011 ◽  
Vol 170 ◽  
pp. 109-113 ◽  
Author(s):  
Anna Bajorek ◽  
Grażyna Chełkowska ◽  
Artur Chrobak ◽  
Marzena Kwiecień-Grudziecka
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Curie Temperature ◽  
Saturation Magnetization ◽  
Intermetallic Compounds ◽  
Applied Magnetic Field ◽  
Magnetic Measurements ◽  
Zero Field ◽  
Zero Field Cooling ◽  
Field Cooling

The paper presents selected magnetic properties of the Gd1-xTbxNi3 intermetallic compounds. Based on the wide-ranging SQUID magnetometer (Quantum Design MPMS, temperature from 1.9K to 300K and magnetic field up to 7T) series of different magnetic measurements were carried out. In studied system the saturation magnetization and the Curie temperature strongly depends of Tb concentration. Moreover, the so-called field cooling - zero field cooling (FC-ZFC) curves reveal a dependence of M(T) on the applied magnetic field. The thermomagnetic curves indicate interesting behaviour which is typical for terbium compounds and can be ascribed to the interaction between different aligned magnetic subblattices.

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

scholarly journals Coherent emission from the stack of Josephson junctions with the non-uniform inductive interaction

2019 ◽  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Gaussian Distribution ◽  
Josephson Junctions ◽  
Critical Currents ◽  
Collective Modes ◽  
Zero Field ◽  
Strong Emission ◽  
Inductive Interaction ◽  
Coherent Emission

During last decade, considerable efforts were made to achieve coherent emission from stacks of many Josephson junctions. It is known that strong emission from a junction in the presence of external magnetic field appears at the so-called Fiske steps in the IV-characteristic at voltages which correspond to frequencies of geometrical resonances. However, it is possible to obtain resonant steps in long junctions without external magnetic field. The periodical movement of fluxons is excited due to some disorder in the distribution of critical currents along junctions. The so-called zero-field steps are formed in the IV-curve due to the interaction of fluxons with oscillations of voltage at Josephson frequencies. We investigated numerically IV-characteristics and the dependence of the average square of ac voltage at the end of the stack of two long Josephson junctions on the average voltage. Junctions interacted inductively with each other. We introduced not only the Gaussian distribution of critical currents along junctions but also the Gaussian distribution of coefficients of the interaction between junctions (mutual inductances). Zero-field steps in the IV-characteristic were found at voltages which corresponded to frequencies of in-phase collective modes in the stack as well as to frequencies of uncoupled junctions. Zero-field steps appeared in the hysteretic region of the IV-curve. There appeared also jumps of voltage from the resistive branch to the zero-field step. We showed that there existed distributions of mutual inductances along junctions which provided jumps to voltages at which the average square of ac voltage at the end of the stack (which is proportional to power of emission) was larger than that for the stack with the uniform distribution of mutual inductances.

scholarly journals Síntesis del superconductor YBa2Cu3O7- δ mediante sinterización por descarga luminiscente anormal

2017 ◽  
Vol 41 (158) ◽  
pp. 36
Author(s):  
Erika Yazmin Soto-Gómez ◽  
Armando Sarmiento-Santos ◽  
Carlos Arturo Parra-Vargas
Keyword(s):  
Zero Field ◽  
Zero Field Cooling ◽  
Field Cooling

En este trabajo se reporta la síntesis del superconductor YBa2Cu3O7-δ mediante el método no convencional de sinterización por plasma en el rango de descarga luminiscente anormal (DLA). Las muestras se sometieron a diferentes temperaturas y tiempos de sinterización. Como referencia se usó una muestra superconductora obtenida por el método convencional (horno resistivo). La caracterización estructural de estas muestras se hizo por difracción de rayos X y refinamiento con el método de Rietveld. El comportamiento superconductor se determinó mediante el análisis de las curvas de magnetización en función de la temperatura según los procedimientos experimentales de enfriado en campo magnético cero (zero field cooling, ZFC) y enfriado con campo magnético aplicado (field cooling, FC). Las muestras sinterizadas por DLA presentaron características estructurales (ortorrómbica Pmmm) y superconductoras con una temperatura crítica de Tc~ 92 K, similares a las obtenidas por el método convencional, pero con una significativa reducción en las temperaturas y tiempos, bajo un ambiente adecuado de presión en el proceso de sinterización. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

Magnetic Prehistory in the Heat Capacity of the Low-Temperature Superconductors

2015 ◽  
Vol 233-234 ◽  
pp. 741-744
Author(s):  
Sergey Mikhailovich Podgornykh
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Ring Specimen ◽  
Trapped Flux ◽  
The Magnetic Field

Effect of the magnetic prehistory on the temperature dependence of the heat capacity of the superconducting Pb, La, Sn. has been studied. As soon as the external magnetic field riches the valueHext=HCthe superconductivity is completely destroyed. The trapped flux was produced in the ring specimen after the magnetic field was turned off atT<TC. We observed a difference of the value of the heat capacity between zero field cooled (ZFC) and field cooled (FC) states in zero magnetic field for the ring specimen. It is found that the FC heat capacity is smaller than the heat capacity both in the normal and in superconducting states.

Induction technique for superconducting rings between field cooling and zero field cooling

2007 ◽  
Vol 459 (1-2) ◽  
pp. 24-26 ◽  
Author(s):  
H. González-Jorge ◽  
I. Quelle ◽  
L. Romaní ◽  
G. Domarco
Keyword(s):  
Zero Field ◽  
Induction Technique ◽  
Superconducting Rings ◽  
Zero Field Cooling ◽  
Field Cooling

Enhanced ferroelectricity and ferromagnetism in La1−xBixCrO3 by Bi3+ substitution

2007 ◽  
Vol 22 (8) ◽  
pp. 2081-2086 ◽  
Author(s):  
H-Y. Guo ◽  
J.I.L. Chen ◽  
Z-G. Ye ◽  
A.S. Arrott
Keyword(s):  
Solid Solution ◽  
Magnetic Properties ◽  
Quantum Interference ◽  
Remanent Polarization ◽  
Magnetic Hysteresis ◽  
Zero Field ◽  
Ferroelectric Hysteresis ◽  
Different Origins ◽  
Zero Field Cooling ◽  
Field Cooling

The ferroelectric and magnetic properties of the perovskite solid solution, (1 − x)LaCrO3–xBiCrO3, have been investigated. While pure LaCrO3 does not show ferroelectric hysteresis even at 77 K, the solid solution of La1−xBixCrO3 with x = 0.1, 0.2, 0.3, and 0.35 displays ferroelectric hysteresis, with the remanent polarization increasing with the increase of the Bi3+ content. Using a superconducting quantum interference device, the magnetization was measured versus temperature under field cooling (FC) and zero field cooling (ZFC) conditions. Magnetic hysteresis has been found in La1−xBixCrO3 (0.1 ⩽ x ⩽ 0.3) below the Néel temperature, TN. With the increase of Bi3+ content, TN decreases, while the magnetization below TN is enhanced. While the ferroelectric and magnetic properties could be due to different origins, the Bi substitution results in both ferroelectric and magnetic enhancements in the (1 − x)LaCrO3–xBiCrO3 solid solutions.

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