Structural, magnetic, and magnetocaloric properties of multiferroic host double perovskite Pr2FeCrO6 compound

Author(s):  
Dipak Mazumdar ◽  
Indranil Das

We have investigated the crystal structure and nature of the magnetic ground state of polycrystalline Pr2FeCrO6 (PFCO) compound through x-ray diffraction (XRD), magnetization, and magnetocaloric effect studies. Analysis of the...

2013 ◽  
Vol 717 ◽  
pp. 133-138
Author(s):  
A. Awad Allah ◽  
M. Elhadi ◽  
O.A. Yassien

The crystal structure of both samples has been solved by powder X-ray diffraction, data in the tetragonal space group I4/m (a= b= 5.55182 Å, c =7.86955 A0) for SrLaFeNi0.5W0.5O6sample and (a=b= 5.49129Å, c= 7.82233Å) for CaLaFeNi0.5W0.5O6 sample, and shows an almost perfect ordering between Ni2+ and W5+ cations at the B-site of the perovskite structure. The FTIR spectrometer used of the powders showed that the spectra of both are very similar, showing two strong and well-defined absorption bands, typical of perovskite materials.


IUCrJ ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 656-662 ◽  
Author(s):  
Daisuke Urushihara ◽  
Sota Kawaguchi ◽  
Koichiro Fukuda ◽  
Toru Asaka

The crystal structure of the spin dimer magnet NaCu2VP2O10 was determined using single-crystal X-ray diffraction and electron diffraction. NaCu2VP2O10 displayed a non-centrosymmetric orthorhombic C2221 structure with a = 6.13860 (10) Å, b = 14.4846 (3) Å and c = 8.2392 (2) Å. The layered structure comprised CuO4 plaquettes, VO6 octahedra and PO4 tetrahedra. A pair of CuO4 plaquettes formed Cu2O6 structural dimers through edge sharing. The Cu–Cu network formed a distorted puckered-layer structure with pseudo-one-dimensional characteristics. Maximum magnetic susceptibility was observed at ∼60 K and NaCu2VP2O10 became non-magnetic upon further cooling. The spin gap between the spin-singlet non-magnetic ground state and triplet excited state was estimated to be 43.4 K. Thus, NaCu2VP2O10 was assumed to be an alternating chain system with a singlet ground state of dimer origin. The V5+ ions in the VO6 octahedra showed large off-centre displacements along the [110] direction in the primitive perovskite structure, which were attributed to the pseudo-Jahn–Teller distortion of d 0 transition metals.


1983 ◽  
Vol 36 (8) ◽  
pp. 1527 ◽  
Author(s):  
BN Figgis ◽  
ES Kucharski ◽  
AH White

The crystal structure of the title compound, [CO(C15H11N3)2] 12.2H2O, has been determined by single crystal X-ray diffraction methods at 295 K and at 120 K, being refined by least squares to residuals of 0.051 and 0.035 respectively for 982 and 1024 'observed' reflections at these temperatures. Both structures are based on a P42/n tetragonal cell, a c. 8.9, c c. 19.4 �, Z 2, in which only a quarter of the cation is independent, being located about a site of 4 symmetry. At room temperature (μoff c. 3.2 BM) Co-N (central, distal) are 1.942(7), 2.104(5) � diminishing to 1.912(5), 2.083(4) � at 120 K, with μoff c. 2.2 BM, corresponding to a fully populated low-spin ground state.


2013 ◽  
Vol 203-204 ◽  
pp. 292-295 ◽  
Author(s):  
Krzysztof Ociepka ◽  
Ania Bajorek ◽  
Artur Chrobak ◽  
Grażyna Chełkowska

The magnetic properties and the crystal structure of the ball-milled Tb(Ni0.95Fe0.05)3compound have been studied by using magnetization measurements and X-ray diffraction (XRD). The results were compared with those obtained for the bulk compound prepared by arc-melting technique. The investigated sample is polycrystalline and crystallizes in the rhombohedral PuNi3type of crystal structure (space group R-3m). With the increase of the time milling (i.e. 1 h, 24 h and 48 h) a for-mation of grains less than 1μm and a reduction of magnetocaloric effect have been observed. The analysis of XRD patterns for ball-milled powders shows that after 48h milling time there is still visible a crystalline structure.


2015 ◽  
Vol 233-234 ◽  
pp. 196-199 ◽  
Author(s):  
Alexey I. Zvonov ◽  
N.Yu. Pankratov ◽  
Dmitriy Karpenkov ◽  
Alexey Karpenkov ◽  
S.A. Nikitin

The melt-spun Y2(Fe,Mn)17ribbons were synthesized by rapid quenching from the melt. The phase composition, crystal structure and magnetocaloric effect (MCE) in low-cost iron-based pseudo-binary Y2(Fe,Mn)17ribbons were investigated respectively by using x-ray diffraction and direct measurements of MCE. It was found that crystal structure of the as-spun ribbons retains hexagonal Th2Ni17-type because of the weak glass-forming ability. The Y2Fe14Mn3and Y2Fe13Mn4nanostructured ribbons demonstrate higher MCE compare to polycrystalline alloys.


2021 ◽  
Vol 33 (3) ◽  
pp. 611-616
Author(s):  
A. Prabhakaran ◽  
M. Arockia Doss ◽  
E. Dhineshkumar ◽  
R. Rajkumar

The title compound 4-(2-(4,5-dimethyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazol-1-yl)morpholine (DMTPM) was synthesized using a one-pot multicomponent approach. The molecular structure of the compound was charcterized with 1H & 13C NMR, HR-MS and single-crystal X-ray diffraction. In the ground-state, DMTPM molecular geometry was determined using the DFT based on B3LYP/6-31G(d,p) and compared to the experimental results. In addition, molecular electrostatic potential (MEP) map and molecular frontier orbitals (MFO) were performed and the results obtained were compatible with the electronic properties.


2021 ◽  
Author(s):  
K.P. Shinde ◽  
E.J. Lee ◽  
Maykel Manawan ◽  
A. Lee ◽  
S.Y. Park ◽  
...  

Abstract Double perovskite Eu2NiMnO6 (ENMO) Gd2NiMnO6 (GNMO) and Tb2NiMnO6 (TNMO) ceramic powder have been synthesized by solid-state reaction and their crystal structure, microstructure, cryogenic magnetic properties, and magnetocaloric performance have been investigated. Structural studies by using X-ray diffraction shows that all compounds crystallize in the monoclinic structure with a P21/n space group. A ferromagnetic to paramagnetic (FM-PM) second-order phase transition occurred in ENMO, GNMO, and TNMO around 143, 130, and 112 K, respectively. The values of maximum magnetic entropy change and relative cooling power at an applied field of 5 T are found to be 3.2, 3.8, 3.5 J/kgK and 150, 182, 176 J/kg respectively, for the studied sample. The change in structural, magnetic, and magnetocaloric effect ascribed to the superexchange mechanism of Ni2+ – O – Mn3+ and Ni2+ – O – Mn4+. Due to different atomic size of Eu, Gd, Tb changes the ratio of Mn4+/Mn3+ which is responsible for the variation of properties significantly in double perovskite.


2018 ◽  
Vol 33 (4) ◽  
pp. 279-286
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
S. H. Lapidus ◽  
L. Ribaud ◽  
S. P. Diwanji

A series of double-perovskite oxides, Sr2RNbO6 (R = Sm, Gd, Dy, Ho, Y, Tm, and Lu) were prepared and their crystal structure and powder diffraction reference patterns were determined using the Rietveld analysis technique. The crystal structure of each of the Sr2RNbO6 phase is reported in this paper. The R = Gd, Ho, and Lu samples were studied using synchrotron radiation, while R = Sm, Dy, Y, and Tm samples were studied using laboratory X-ray diffraction. Members of Sr2RNbO6 are monoclinic with a space group of P21/n and are isostructural with each other. Following the trend of “lanthanide contraction”, from R = Sm to Lu, the lattice parameters “a” of these compounds decreases from 5.84672(10) to 5.78100(3) Å, b from 5.93192(13) to 5.80977(3) Å, c from 8.3142(2) to 8.18957(5) Å, and V decreases from 288.355(11) to 275.057(2) Å3. In this double-perovskite series, the R3+ and Nb5+ ions are structurally ordered. The average Nb–O bond length is nearly constant, while the average R–O bond length decreases with the decreasing ionic radius of R3+. Powder diffraction patterns for these compounds have been submitted to the Powder Diffraction File (PDF).


2018 ◽  
Vol 73 (10) ◽  
pp. 739-747 ◽  
Author(s):  
Lukas Heletta ◽  
Sebastian Stein ◽  
Rainer Pöttgen

AbstractThe magnetocaloric effect (MCE) of the ferromagnetic compound GdAg2Mg [TC=98.3(5) K] was investigated along with its electrical resistivity and the specific heat capacity. The magnetic entropy changes (–ΔSM) as well as the changes in adiabatic temperature (ΔTad) have been calculated from these data. Furthermore, the magnetic susceptibility of the pseudo-quaternary Heusler phases GdAgAuMg, TbAgAuMg and DyAgAuMg [i.e. RE(Ag0.5Au0.5)2Mg] were measured and compared to the data for the pure silver and gold compounds REAg2Mg and REAu2Mg. The substitution of the transition metal at the crystallographic Wyckoff site 8c influences the magnetic ground state of the trivalent rare earth metals and therefore drastically alters the Curie temperatures. The structure of GdAgAuMg was refined from single crystal X-ray diffraction data, revealing a small deviation from the equiatomic composition leading to the refined formula GdAg0.92(6)Au1.08(6)Mg [space group Fm3̅m, Z=4, a=695.03(10) pm, wR2=0.0883, 55 F2 values, six parameters]. The intermetallic compounds were synthesised in sealed niobium ampoules under high temperature conditions. They have reddish to brassy colour.


2012 ◽  
Vol 9 (2) ◽  
pp. 772-779 ◽  
Author(s):  
H. Marouani ◽  
N. Raouafi ◽  
S. Toumi Akriche ◽  
S. S. Al-Deyab ◽  
M. Rzaigui

Reaction of phenylpiperazine and nitric acid yields the new organicinorganic hybrid material of phenylpiperazinium (C10H16N2)(NO3)2.H2O, (I). To understand the interaction between components of this salt, single crystal structure and computational studies are performed and reported. X-ray diffraction analysis was employed for the structural characterization. Computational methods were exploited for ground state structure determination and HOMO-LUMO calculations were determined. Detailed studies on ground state structure determinations as well as Electrostatic Potential Surface maps have been estimated by applying second-order Møller- Plesset (MP2) perturbation theory.


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