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.

Microstructural and Magnetic Properties on Graphitic Encapsulated Ni Nanocrystals and Pure Ni Nanoparticles with NiO Layer

1999 ◽  
Vol 581 ◽  
Author(s):  
Xiangcheng Suns ◽  
M. Jose Yacamana ◽  
F. Morales
Keyword(s):  
Magnetic Properties ◽  
Room Temperature ◽  
Nickel Nanoparticles ◽  
Blocking Temperature ◽  
Morphological Properties ◽  
Zero Field ◽  
Ni Nanoparticles ◽  
Ferromagnetic Interaction ◽  
Zero Field Cooling ◽  
Field Cooling

ABSTRACTTwo kinds of different nickel nanoparticles with distinct morphological properties, Ni(C) and Ni(O), are studied. Magnetization measurements for the assembly of two kinds of Ni nanoparticles show, a larger coercivity and remanence as well as the deviation between the zero field cooling (ZFC) and the field cooling (FC) magnetization have been observed in the Ni(O) particles. This deviation may be explained as a typical cluster glass-like behavior due to ferromagnetic interaction among the assembly of Ni(O) particles. However, Ni(C) particles exhibit superparamagnetism at room temperature. The average blocking temperature (TB) is determined to around 115K. We also observe gradual decrease in saturation magnetization, which is attributed to the nanocrystalline nature of the encapsulated particles.

scholarly journals Magnetic properties of iron oxide nanoparticles with a DMSA-modified surface

2021 ◽  
Vol 242 (1) ◽  
Author(s):  
K. Winiarczyk ◽  
W. Gac ◽  
M. Góral-Kowalczyk ◽  
Z. Surowiec
Keyword(s):  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Magnetic Hysteresis ◽  
Blocking Temperature ◽  
Synthesis Process ◽  
Physical Parameters ◽  
Zero Field ◽  
Powder Samples ◽  
Surface Modified ◽  
Field Cooling

AbstractThe magnetic properties of magnetite nanoparticles (Fe3O4 NPs) strongly depend on their chemical and physical parameters, which can be regulated by a controlled synthesis process. To improve the quality of the obtained nanoparticles, their surface is often modified with organic compounds (from the group of surfactants, sugars, proteins, or organic acid). In this study, we synthesized magnetite nanoparticles with a surface modified with the organic compound DMSA. Then, the nanocrystallites were characterized in terms of structure and morphology. To investigate the role of DMSA and to understand the adsorption mechanism, FTIR measurements were carried out. Using Mössbauer spectroscopy, we investigated temperature-induced changes in the magnetic properties of prepared samples. The spectra were recorded in a wide temperature range (from 4 K to 390 K) for two types of samples: powders and ferrofluids with various concentrations. In the case of powder samples, the superparamagnetic doublet appeared at room temperature. For magnetic suspensions, the spectra were more complicated. They consisted of superposition of asymmetrically broadened sextets and doublets, which was caused by the occurrence of long-range dipole-dipole interactions. These interactions affected the magnetic properties of the material and increased the blocking temperature. Additionally, the magnetic hysteresis and zero field cooling-field cooling (ZFC/FC) curves were measured with the use of a vibrating sample magnetometer.

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 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.

scholarly journals Iron-Doped Lithium Tantalate Thin Films Deposited by Magnetron Sputtering: A Study of the Iron Role in the Structure and the Derived Magnetic Properties

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 50 ◽  
Author(s):  
Sergio David Villalobos Mendoza ◽  
José Trinidad Holguín Momaca ◽  
José Trinidad Elizalde Galindo ◽  
Diana María Carrillo Flores ◽  
Sion Federico Olive Méndez ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Blocking Temperature ◽  
Ferromagnetic Behavior ◽  
Zero Field ◽  
Cooling Curves ◽  
X Ray Diffraction ◽  
Field Cooling

Fe-doped LiTaO3 thin films with a low and high Fe concentration (labeled as LTO:Fe-LC and LTO:Fe-HC, respectively) were deposited by magnetron sputtering from two home-made targets. The dopant directly influenced the crystalline structure of the LiTaO3 thin films, causing the contraction of the unit cell, which was related to the incorporation of Fe3+ ions into the LiTaO3 structure, which occupied Li positions. This substitution was corroborated by Raman spectroscopy, where the bands associated with Li-O bonds broadened in the spectra of the samples. Magnetic hysteresis loops, zero-field cooling curves, and field cooling curves were obtained in a vibrating sample magnetometer. The LTO:Fe-HC sample demonstrates superparamagnetic behavior with a blocking temperature of 100 K, mainly associated with the appearance of Fe clusters in the thin film. On the other hand, a room temperature ferromagnetic behavior was found in the LTO:Fe-LC layer where saturation magnetization (3.80 kAm−1) and magnetic coercivities were not temperature-dependent. Moreover, the crystallinity and morphology of the samples were evaluated by X-ray diffraction and scanning electron microscopy, respectively.

Effects of Na-Doping on Structure and Magnetic Properties of LaCoO3

2017 ◽  
Vol 727 ◽  
pp. 403-409
Author(s):  
Yi Hao Shen ◽  
Qing Rong Yao ◽  
Peng Cheng Yang ◽  
Jian Qiu Deng ◽  
Zong Min Wang
Keyword(s):  
Magnetic Properties ◽  
Structure Refinement ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Zero Field ◽  
Ferromagnetic Transition ◽  
Na Doping ◽  
Crystallite Sizes ◽  
Field Cooling

Effect of Na doping on the structural and magnetic properties of La1-xNaxCoO3 (0≤x≤0.4) nanopowder samples synthesized by sol-gel method have been investigated. Rietveld crystal structure refinement of the X-ray diffraction data shows that La1−xNaxCoO3 (x≤0.3) crystallizes in the rhombohedral structure with space group . The lattice parameters decrease and the crystallite sizes increase with the increase of x. For the sample with x=0.4, a secondary hexagonal phase NaCo2O4 was observed. The zero field cooling (ZFC) and field cooling (FC) curve of the samples (x≤0.3) exhibit a paramagnetic-ferromagnetic transition with decreasing temperature.

scholarly journals Ferroelectric and Magnetic Properties of Hot-Pressed BiFeO3-PVDF Composite Films

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Annapu V. Reddy ◽  
K. C. Sekhar ◽  
Navneet Dabra ◽  
A. Nautiyal ◽  
Jasbir S. Hundal ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Coercive Field ◽  
Polyvinylidene Fluoride ◽  
Room Temperature ◽  
Magnetic Hysteresis ◽  
Composite Films ◽  
Hysteresis Loops ◽  
Liquid Phase Sintering ◽  
Magnetic Hysteresis Loops ◽  
Ferroelectric Hysteresis

The ferroelectric and magnetic properties of hot-pressed BiFeO3- (BFO) polyvinylidene fluoride (PVDF) composite films have been studied. The BiFeO3 (BFO) ceramics have been synthesized by a rapid liquid phase sintering technique. The X-ray diffraction (XRD) studies revealed that the impure phase observed in pure BFO ceramics was significantly reduced in the composite films. The presence of both ferroelectric and magnetic hysteresis loops confirms the multiferroic nature of the composite films at room temperature. A well-saturated ferroelectric hysteresis loop with a remanent polarization (Pr)∼4.8 μC-cm-2 and coercive field (Ec)∼1.55 kV/cm has been observed in composite thin films at room temperature. The magnetic hysteresis loops were traced at room temperature with SQUID. The remanent magnetization (Mr)∼3.0×10−3 emu/gm and coercive field (Hc)∼0.99 kOe was observed in the composite film. The magnetic polarization of the composite films has found to be enhanced as compared to pure BFO and correlated to reduction in BFO impure peak intensity.

Sign in / Sign up

Export Citation Format

Share Document