Zero-field ferroelectric state and magnetoelectric coupling in antiferromagnetic Fe4Nb2O9 single crystal

2020 ◽  
Author(s):  
Yunke Chen ◽  
Xiong Luo ◽  
Xiaoxuan Ma ◽  
Chao Xu ◽  
Baojuan Kang ◽  
...  
Keyword(s):  
Single Crystal ◽  
Magnetoelectric Coupling ◽  
Zero Field ◽  
Ferroelectric State

Spontaneous phase transition from relaxor to macrodomain ferroelectric state in single-crystal PbSc0.5Nb0.5O3-BaSc0.5Nb0.5O3 solid solutions

2000 ◽  
Vol 42 (1) ◽  
pp. 161-164 ◽  
Author(s):  
I. P. Raevskii ◽  
V. V. Eremkin ◽  
V. G. Smotrakov ◽  
E. S. Gagarina ◽  
M. A. Malitskaya
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Solid Solutions ◽  
Ferroelectric State ◽  
Spontaneous Phase

Electronic structure of PbSc1/2Nb1/2O3 single-crystal ferroelectric-relaxor in the paraelectric and ferroelectric state

2017 ◽  
Vol 666 ◽  
pp. 1-8 ◽  
Author(s):  
A.T. Kozakov ◽  
O.E. Polozhentsev ◽  
I.P. Raevski ◽  
N. Kumar ◽  
S.I. Raevskaya ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Single Crystal ◽  
Ferroelectric State ◽  
Ferroelectric Relaxor

scholarly journals Influence of Crystallite Size on the Magnetic Order in Semiconducting ZnCr2Se4 Nanoparticles

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3947 ◽  
Author(s):  
Ewa Malicka ◽  
Małgorzata Karolus ◽  
Tadeusz Groń ◽  
Adrian Gudwański ◽  
Andrzej Ślebarski ◽  
...  
Keyword(s):  
Single Crystal ◽  
Specific Heat ◽  
Spin Glass ◽  
Crystallite Size ◽  
Magnetic Order ◽  
Ac Susceptibility ◽  
High Energy ◽  
Zero Field ◽  
Bulk Single Crystal ◽  
Field Cooling

Structural, electrical, magnetic, and specific heat measurements were carried out on ZnCr2Se4 single crystal and on nanocrystals obtained from the milling of this single crystal after 1, 3, and 5 h, whose crystallite sizes were 25.2, 2.5, and 2 nm, respectively. For this purpose, the high-energy ball-milling method was used. The above studies showed that all samples have a spinel structure, and are p-type semiconductors with less milling time and n-type with a higher one. In turn, the decrease in crystallite size caused a change in the magnetic order, from antiferromagnetic for bulk material and nanocrystals after 1 and 3 h of milling to spin-glass with the freezing temperature Tf = 20 K for the sample after 5 h of milling. The spin-glass behavior for this sample was derived from a broad peak of dc magnetic susceptibility, a splitting of the zero-field-cooling and field-cooling susceptibilities, and from the shift of Tf towards the higher frequency of the ac susceptibility curves. A spectacular result for this sample is also the lack of a peak on the specific heat curve, suggesting a disappearance of the structural transition that is observed for the bulk single crystal.

scholarly journals Low-T magnetic anomaly in Ca2Fe2O5studied by single-crystal neutron diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1352-C1352
Author(s):  
Josie Auckett ◽  
Garry McIntyre ◽  
Maxim Avdeev ◽  
Hank De Bruyn ◽  
Chris Ling
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Temperature Interval ◽  
Diffraction Data ◽  
Room Temperature ◽  
Statistical Significance ◽  
Spin Reorientation ◽  
Careful Examination ◽  
Zero Field ◽  
Zone Method

Ca2Fe2O5, which belongs to the Brownmillerite family of promising solid-oxide fuel cell membrane materials, is an antiferromagnet (AFM) below TN = 720 K. A small ferromagnetic (FM) canting perpendicular to the AFM easy axis has previously been established by physical properties measurements, but never observed crystallographically. More intriguingly, it has been known for some time to display an anomalous elevation in magnetic susceptibility for 60 K < T < 140 K. [1] Based on measurements performed with small oriented single crystals, Zhou et al. [2] proposed that this anomaly was due to a reorientation of the spins from the crystallographic a axis to the c axis below 40 K, with a region of minimal magnetocrystalline anisotropy in the anomalous temperature interval. In order to test this, we grew a very large (~1 cm3) single crystal by the floating-zone method and collected neutron Laue diffraction data, against which we refined both the atomic and magnetic structures of Ca2Fe2O5 between 10 K and 300 K. We designed and built an ad hoc sample mount to apply a small (~35 Oe) magnetic field to the sample, ensuring perfect consistency with the magnetic susceptibility data, which were collected in a comparably small field. Our refinements against both zero-field and in-field diffraction data reproduce the G-type AFM structure of Ca2Fe2O5 excellently at room temperature, including the FM canting which we have refined to statistical significance for the first time. We can also show that in the intermediate temperature interval (T = 100 K), the spins are slightly less well-ordered due to competing sublattice interactions. However, careful examination of the data reveals that the material is still best described by the room-temperature magnetic structure at all measured temperatures – i.e., the spin-reorientation hypothesis is incorrect.

Ferroelectricity, ferromagnetism, and magnetoelectric coupling in highly textured thin films of the multiferroic Pb(Fe0.5Nb0.5)O3

2012 ◽  
Vol 1454 ◽  
pp. 51-56 ◽  
Author(s):  
Oscar Raymond-Herrera ◽  
Paola Góngora-Lugo ◽  
Carlos Ostos ◽  
Mario Curiel-Alvarez ◽  
Dario Bueno-Baques ◽  
...  
Keyword(s):  
Thin Films ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Magnetoelectric Coupling ◽  
Ferroelectric Materials ◽  
Zero Field ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis ◽  
First Time ◽  
Magnetization Behavior

ABSTRACTA study of the ferroelectric and magnetic properties and of the magnetoelectric coupling effects of Pb(Fe0.5Nb0.5)O3 (PFN) thin films, grown on SrRuO3/Si [(100) or (111)] substrates by the rf-magnetron sputtering technique, is presented. Structural, morphological, and compositional characterization was realized using the XRD, AFM, XPS, and TEM techniques. Highly textured single phase films with different thickness (from 45 to 270 nm) were successfully grown without Fe2+ presence. A vertically [110] oriented grainy structure was observed. Polarization vs. electric field (P-E) hysteresis loops exhibit excellent and almost constant values of the maximum (∼ 60 μC/cm2) and remanent (∼ 22 μC/cm2) polarizations in the temperature range from 4 K to room temperature; small values of the coercive field, characteristic of soft ferroelectric materials, are observed in these samples. Measurements of the zero-field cooled (ZFC) and field cooled (FC) magnetization behavior and magnetic (M-H) hysteresis loops were realized at different temperatures between 5 and 300 K. Proof of the existence of ferromagnetic order in the low temperature region (below to 50 K) is discussed and reported for the first time. Values of the maximum (∼ 3 emu/g) and remanent (∼ 1.5 emu/g) magnetizations were obtained. dc magnetic field dependence of the ferroelectric hysteresis loops are shown as evidence of the magnetoelectric coupling.

(CH3)3CCOOSbCl4: Structure Determination by Zeeman Perturbed NQR

1986 ◽  
Vol 41 (1-2) ◽  
pp. 129-133 ◽  
Author(s):  
Maria L. S. Garcia ◽  
Edwin A. C. Lucken
Keyword(s):  
Molecular Structure ◽  
Magnetic Field ◽  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Organic Ligand ◽  
Coupling Constants ◽  
Zero Field ◽  
Quadrupole Coupling ◽  
Asymmetry Parameters

A single crystal of tetrachloro(0,0-pivaloylato)antimony(V) has been studied at 77 K, byZeeman perturbed 35Cl NQR, using a FT-NQR pulsed spectrometer. The four lines at zero-field, ν1 = 27.6468, ν2= 27.3070, ν3= 25.7341 and ν4= 25.3438 MHz yield eight EFG tensors in themagnetic field, related by a twofold symmetry element in the crystal. The correspondingasymmetry parameters are η1, = 0.134, η2 = 0.13, η3= 0.07, and η4 = 0.09. The molecular structurededuced from the relative orientations of the principal Z-axes of the EFG tensors confirms that thehigher quadrupole coupling constants are associated with the chlorine atoms in equatorial positions,relative to the plane of the organic ligand, as predicted from NQR powder studies. It is concludedthat the crystal structure is monoclinic with two (class m or 2) or four (class 2/m) moleculesper unit cell. The molecular packing is such that the planes formed by equatorial or axial chlorineatoms are approximately at right angles to their symmetry related images.

Sign in / Sign up

Export Citation Format

Share Document