Designing room-temperature multiferroic materials in a single-phase solid-solution film

Magnetoelectric effect in multiferroic materials is widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, Pb(Fe0.5Nb0.5)O3is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetostrictive and magnetoelectric properties of nickel ferrite Ni0.3Zn0.62Cu0.08Fe2O4- relaxor Pb(Fe0.5Nb0.5)O3bulk composites. The magnetic properties of composites shows a dependence typical of such composite materials, i.e. it consists of a dominating signal from ferrimagnetic phase (ferrite) and a weak signal from paramagnetic (antiferromagnetic) phase (relaxors). Magnetoelectric effect at room temperature was investigated as a function of static magnetic field (300-7200 Oe) and frequency (10 Hz-10 kHz) of sinusoidal modulation magnetic field. The magnetoelectric effect increase slightly before reaching a maximum at HDC= 750 Oe and then decrease. The magnetoelectric coefficient increases continuously as frequency is raised, although this increase is less pronounced in the 1-10 kHz range.

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Emerging Technologies and Opportunities Based on the Magneto-Electric Effect in Multiferroic Composites

MRS Proceedings ◽

10.1557/proc-1161-i05-04 ◽

2009 ◽

Vol 1161 ◽

Cited By ~ 5

Author(s):

Marian Vopsaroiu ◽

John Blackburn ◽

Markys G. Cain

Keyword(s):

Room Temperature ◽

Single Phase ◽

Emerging Technologies ◽

Academic Research ◽

Multiferroic Materials ◽

Composite Systems ◽

Enhanced Properties ◽

The Many ◽

Electric Effect ◽

Laminated Structures

AbstractMultiferroic materials are recognized today as one of the new emerging technologies with huge potential for both academic research and commercial developments. Multiferroic composites are in particular more attractive for studies due to their enhanced properties, especially at room temperature, in comparison to the single-phase multiferroics. In this paper, we examine some of the theoretical aspects regarding one type of multiferroic composites (laminated structures) and we discuss one of the many possible applications of these exciting structures. We highlight the main advantages composite systems have over single-phase multiferroics and the similarities that exist between them.

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Preparation and Characterization of Well-Dispersed Nd1.6Eu0.4Zr2O7 Solid Solution and its Fluorescent Behavior

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.182 ◽

2010 ◽

Vol 97-101 ◽

pp. 182-186

Author(s):

Yu Ping Tong ◽

Jing Wang ◽

Rui Zhu Zhang ◽

Shun Bo Zhao

Keyword(s):

Solid Solution ◽

Solid Solutions ◽

Room Temperature ◽

Single Phase ◽

Combustion Process ◽

Crystal Form ◽

Scherrer Formula ◽

Xrd Patterns ◽

Average Size

Well-dispersed Nd1.6Eu0.4Zr2O7 solid solutions were successfully prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by XRD, Raman, TEM and HRTEM. The results showed that the Nd ion can be partially replaced by Eu ion. The substituted product was still single-phase solid solutions and the crystal form remained unchanged. TEM images showed that the Nd1.6Eu0.4Zr2O7 solid solutions were composed of well-dispersed sphere-shaped nanocrystals with an average size of 30 nm, which is consistent with the value obtained from XRD patterns using the Scherrer formula. Moreover, the fluorescent characterization of the Nd1.6Eu0.4Zr2O7 nanocrystals at 385 nm upon excitation was carried out at room temperature, and the results showed that there were some intense and prevailing emission peaks located at 590-650 nm.

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The preparation and electrical properties of TiO2−xFx

Journal of Materials Research ◽

10.1557/jmr.1988.0392 ◽

1988 ◽

Vol 3 (2) ◽

pp. 392-397 ◽

Cited By ~ 10

Author(s):

Tadashi Endo ◽

Naoki Morita ◽

Tsugio Sato ◽

Masahiko Shimada

Keyword(s):

Solid Solution ◽

Electrical Properties ◽

Diffraction Data ◽

Room Temperature ◽

Single Phase ◽

Fluorine Content ◽

Band Model ◽

Electric Conduction ◽

Electrical Resistivities ◽

The Relationship

The substitution of fluorine for oxygen in TiO2 was investigated by the reaction of Ti2O3, TiO2, and TiF3 under conditions of 4–6.5 GPa and 700–1400°C. The single phase of TiO2−x Fx solid solution was obtained in the region of 0≤x≤0.7. According to the x-ray diffraction data, the a and c axes of the rutile-type structure linearly increased with increasing fluorine content. The electrical resistivities of TiO2−x Fx were in the range from 10 Ω cm for x = 0.3 to 850 Ω cm for x = 0.7 at 300 K and the relationship between In ρ and 1000/T was linear. The activation energies were estimated to be from 0.17 eV at x = 0.3 to 0.28 eV at x = 0.7. Also, the thermoelectric powers at room temperature changed from 250μV/K to + 50 μV/K. The mechanism of electric conduction was discussed on the basis of the extended band model of rutile.

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Piezoelectric Ba and Ti co-doped BiFeO3 textured films: selective growth of solid solutions or nanocomposites

Journal of Materials Chemistry C ◽

10.1039/d0tc03930f ◽

2020 ◽

Vol 8 (45) ◽

pp. 16168-16179

Author(s):

Quentin Micard ◽

Anna L. Pellegrino ◽

Raffaella Lo Nigro ◽

Ausrine Bartasyte ◽

Guglielmo G. Condorelli ◽

...

Keyword(s):

Solid Solution ◽

Solid Solutions ◽

Process Parameters ◽

Single Phase ◽

Selective Growth ◽

Nanocomposite Sample ◽

Co Doped ◽

Solid Solution Film

Accurate control of the MOCVD process parameters results selectively and reproducibly in the formation of two different systems: a single-phase solid solution film and a nanocomposite sample formed by nanocolumns embedded in a solid solution film.

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Room Temperature Exchange Bias in Structure-Modulated Single-Phase Multiferroic Materials

Chemistry of Materials ◽

10.1021/acs.chemmater.8b02798 ◽

2018 ◽

Vol 30 (17) ◽

pp. 6156-6163 ◽

Cited By ~ 11

Author(s):

Guopeng Wang ◽

Zezhi Chen ◽

Hongchuan He ◽

Dechao Meng ◽

He Yang ◽

...

Keyword(s):

Exchange Bias ◽

Room Temperature ◽

Single Phase ◽

Multiferroic Materials ◽

Temperature Exchange

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The C14-to-C15 Transformation in Cr2Hf

MRS Proceedings ◽

10.1557/proc-364-1383 ◽

1994 ◽

Vol 364 ◽

Cited By ~ 3

Author(s):

K. S. Kumar ◽

P. M. Hazzledine

Keyword(s):

Heat Treatment ◽

Phase Diagram ◽

Solid Solution ◽

Elevated Temperature ◽

Room Temperature ◽

Single Phase ◽

Higher Order ◽

Two Phase ◽

Heat Treated ◽

Order Structures

AbstractThree alloys, single-phase Cr2Hf, a two-phase alloy consisting of Cr solid solution and Cr2Hf, and a two-phase alloy consisting of Hf solid solution and Cr2Hf were cast and heat treated. The C14-to- C15 transformation of the Laves phase, Cr2Hf was studied as a function of heat treatment. According to the existing phase diagram, the Cr2Hf phase exhibits a C14 structure at elevated temperature but transforms to the C15 structure at lower temperatures. Such transformations are known to be extremely sluggish. In the present study, the Cr2Hf phase was found to retain the C14 structure at room temperature in all three compositions in the cast or cast and forged conditions; upon subsequent heat-treatment at various temperatures and time-at-temperatures, however, the C14 structure decomposes to a variety of higher order structures including the 16H, 10H, and 4H structures. These superstructures can be viewed as containing various percentages of the cubic and hexagonal stacking. The C15 structure was not observed for any of the conditions considered.

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Interface Resistance of an SOFC Cathode with a Pr1-xTbxO2-d Active Layer

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac44b7 ◽

2021 ◽

Author(s):

Reiichi Chiba ◽

Rin Kawaguchi ◽

Kazuma Horie

Keyword(s):

Phase Transition ◽

Solid Solution ◽

Active Layer ◽

Room Temperature ◽

Single Phase ◽

Fluorite Structure ◽

Impedance Method ◽

Sofc Cathode ◽

Interface Resistance ◽

Better Than

Abstract We investigated the use of Pr1-xTbxO2-d (x=0.0-1.0) material for active layer in SOFC cathode. Pr1-xTbxO2-d (x=0.0-1.0) in single-phase fluorite structure were successfully synthesized. They are solid solution of Pr6O11 and Tb4O7. When the x is between 0.3 and 0.6, the phase transition between room temperature and 800oC were eliminated Coin cells with GDC electrolyte and Pr1-xTbxO2-d (x=0.0-1.0) active layer and LaNi0.6Fe0.4O3 (LNF) current collecting layer were made to clarify the effect of this active layer. The interface resistance of these cathodes was measured with an AC impedance method at 800oC. The cathodes withPr1-xTbxO2-d (for all composition) active layer performed better than that of reference cathode, which has no active layer (consisting only LNF layer).

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