scholarly journals Directed synthesis of a hybrid improper magnetoelectric multiferroic material

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tong Zhu ◽  
Fabio Orlandi ◽  
Pascal Manuel ◽  
Alexandra S. Gibbs ◽  
Weiguo Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Magnetic Moment ◽  
Ferroelectric Material ◽  
Polar Phase ◽  
Antiferromagnetic State ◽  
Exchange Reactions ◽  
Polar Structure ◽  
Directed Synthesis ◽  
Atom Displacement ◽  
Spontaneous Magnetic Moment

AbstractPreparing materials which simultaneously exhibit spontaneous magnetic and electrical polarisations is challenging as the electronic features which are typically used to stabilise each of these two polarisations in materials are contradictory. Here we show that by performing low-temperature cation-exchange reactions on a hybrid improper ferroelectric material, Li2SrTa2O7, which adopts a polar structure due to a cooperative tilting of its constituent TaO6 octahedra rather than an electronically driven atom displacement, a paramagnetic polar phase, MnSrTa2O7, can be prepared. On cooling below 43 K the Mn2+ centres in MnSrTa2O7 adopt a canted antiferromagnetic state, with a small spontaneous magnetic moment. On further cooling to 38 K there is a further transition in which the size of the ferromagnetic moment increases coincident with a decrease in magnitude of the polar distortion, consistent with a coupling between the two polarisations.

A low-temperature study of the magnetic properties of the molecular cations O2+, Br2+, and I2+

1989 ◽  
Vol 67 (11) ◽  
pp. 1942-1948 ◽  
Author(s):  
M. S. R. Cader ◽  
R. C. Thompson ◽  
F. Aubke
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Magnetic Moment ◽  
Photoelectron Spectroscopy ◽  
Theoretical Models ◽  
Antiferromagnetic Coupling ◽  
Paramagnetic Species ◽  
Magnetic Studies ◽  
Suggested Keywords ◽  
Molecular Cations

Magnetic susceptibility measurements to 4.2 K are reported forO2+[AsF6]−, Br2+[Sb3F16]−, and I2+[Sb2F11]−. The data are interpreted utilizing previous results from photoelectron spectroscopy, known crystal structures, magnetic studies on the superoxide ion and the ozonide ion, and in the case of O2+[AsF6]−, previous ESR studies. The magnetic properties of the three materials are quite different. Br2+[Sb3F16]− obeys Curie–Weiss law between 80 and 4 K: Cm = 0.49 ± 0.01 cm3 mol−1 K and 9 = −0.74 ± 0.01 K (with TIP = 120 × 10−6 cm3 mol−1). The magnetic moment decreases slightly from 2.04 μB at room temperature to 1.93 μB at 4 K. I2+[Sb2F11]− exhibits relatively strong antiferromagnetic coupling with a maximum in χM observed at −54 K. The magnetic moment (corrected for a TIP contribution of 68 × 10−6 cm3 mol−1) decreases from 1.92 μB at 124 K to 0.41 μB at 4 K. Experimental susceptibilities for this compound over the range 300–4 K have been compared to values calculated using three different theoretical models for extended chains of antiferromagnetically coupled paramagnetic species. O2+[AsF6]− exhibits Curie–Weiss behaviour over the range 60–2 K (Cm = 0.34 ± 0.01 cm3 mol−1 K, θ = −1.90 ± 0.01 K). The magnetic moment, uncorrected for TIP, varies from 1.63 μB at 80 K to 1.17 μB at 2 K, and the presence of weak antiferromagnetic coupling in this material is suggested. Keywords: magnetic susceptibilities, dihalogen cations, dioxygenyl cation, low temperature behaviour.

Low-temperature nonlinear effects in the conductivity of lightly doped cuprates La2−xSrxCuO4in antiferromagnetic state

2014 ◽  
Vol 40 (5) ◽  
pp. 397-407 ◽  
Author(s):  
N. V. Dalakova ◽  
B. I. Belevtsev ◽  
E. Yu. Belyaev ◽  
A. S. Panfilov ◽  
N. P. Bobrysheva ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nonlinear Effects ◽  
Antiferromagnetic State

Tieftemperatur-Raman-Messungen an bewegten Proben bei 10 K am Beispiel der Isotopomeren Cs2[Pt35Cln37Cl6-n, n = 0-6 / Low-Temperature Raman Measurements on Moved Samples at 10 K Exemplified by the Isotopomers Cs2[Pt35Cln 37Cl6-n], n = 0-6

1993 ◽  
Vol 48 (12) ◽  
pp. 1737-1741 ◽  
Author(s):  
W. Preetz ◽  
E. Parzich
Keyword(s):  
Low Temperature ◽  
Ligand Exchange ◽  
Room Temperature ◽  
Valence Vibration ◽  
Closed Cycle ◽  
Exchange Reactions ◽  
Normal Coordinate ◽  
Point Groups ◽  
Isotopic Effects ◽  
Good Agreement

A technique to record Raman spectra of deeply coloured solids at low temperature (10 K) is described, using a closed cycle He-cryogenerator and moving the cell by an excentric attachment. The spectroscopic resolution is considerably enhanced as compared to room temperature or 80 K measurements. This is obvious from splittings of Raman lines observed at 10 K on the isotopomers Cs2[Pt35Cln37Cl6-n], n = 1 -5, which have been prepared by stereospecific ligand exchange reactions. As a consequence of lowered symmetry the degenerate valence vibration v2(Eg, Oh) is split into two lines for the isotopomers belonging to the point groups D4h, C4v and C2v. The isotopic effects calculated by normal coordinate analysis are in good agreement with the observed frequencies.

Transition from Itinerant Electron Magnetism to Localized Spin Magnetism in Ni3Al1-YMny Alloys

2010 ◽  
Vol 168-169 ◽  
pp. 149-152 ◽  
Author(s):  
A.V. Korolyov ◽  
N.I. Kourov ◽  
S.Z. Nazarova ◽  
Y.A. Dorofeev ◽  
N.V. Volkova ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Magnetic Moment ◽  
Effective Magnetic Moment ◽  
Average Distance ◽  
Magnetic Moments ◽  
Itinerant Electron ◽  
Spin Magnetism ◽  
Spontaneous Magnetic Moment

Magnetic properties of Ni3Al1-yMny alloys at y≤0.6 were investigated at T≤400 K in magnetic fields H≤4 MA/m. The concentration y dependencies of the spontaneous magnetic moment s, the effective magnetic moment eff, the Curie temperature ТС, the Weiss constant , and the temperature independent part of the magnetic susceptibility 0 were determined. The behavior of the Rhodes-Wohlfarth parameter р(y) in the transition region from the itinerant electron magnetism to the spin localized one is related to the increase in the spontaneous magnetic moment of Ni atoms inversely proportional to the average distance between Mn atoms with the highly localized magnetic moments.

(NH4)2S, a highly reactive molecular precursor for low temperature anion exchange reactions in nanoparticles

2013 ◽  
Vol 42 (35) ◽  
pp. 12596 ◽  
Author(s):  
Haitao Zhang ◽  
Louis V. Solomon ◽  
Don-Hyung Ha ◽  
Shreyas Honrao ◽  
Richard G. Hennig ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anion Exchange ◽  
Exchange Reactions ◽  
Molecular Precursor

MAGNETIC PROPERTIES OF R2In (R=Gd, Tb, Er)

1993 ◽  
Vol 07 (01n03) ◽  
pp. 818-821 ◽  
Author(s):  
D. RAVOT ◽  
O. GOROCHOV ◽  
T. ROISNEL ◽  
G. ANDRE ◽  
F. BOUREE-VIGNERON ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Antiferromagnetic State ◽  
Powder Neutron Diffraction ◽  
Magnetic Transport ◽  
The Rare Earth

For all the Rare-Earth (R) the R2In form in the same crystal structure (P63/mmc). These compounds show a great variety of magnetic behaviors. When the temperature decreases, the magnetic susceptibility of Er2InTb2In and Gd2In increases, passes through a maximum then decreases. For Gd2In this behavior was associated with change from a paramagnetic to a ferromagnetic then to an antiferromagnetic state. We have performed magnetic, transport (Tb, Er), Mössbauer spectroscopy (Er) and powder neutron diffraction experiments (Gd, Tb, Er) on these compounds. Unlike Gd2In the resistivity of Tb2In and Er2In does not reveal any anomaly at the temperature where the susceptibility begins to decrease and the Tb2In and Er2In magnetizations show the same behavior at all temperatures in the ordered region. Neutron diffraction experiments reveal ferromagnetic and antiferromagnetic structures at low temperature.

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