Implications of Interfacial Coupling and Strain on the Magnetic and Structural Ordering of Fe3O4/NiO Superlattices

1994 ◽  
Vol 341 ◽  
Author(s):  
David M. Lind
Keyword(s):  
Molecular Beam ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Interlayer Coupling ◽  
Verwey Transition ◽  
Interfacial Coupling ◽  
Adjacent Layer ◽  
Structural Ordering ◽  
X Ray

AbstractHere we review recent work on the preparation and characterization of magnetically ordered oxide Fe3O4/NiO superlattices. The materials were prepared by oxygen plasma-assisted molecular beam epitaxy. Their structural ordering was studied by x-ray, neutron, and RHEED electron diffraction techniques, and the superlattices are found to form as highly coherent strained-layer modulated single crystals. The magnetic ordering studies, using SQUID magnetometry, ferromagnetic resonance, and neutron diffraction, indicated strong interfacial coupling between the ferrimagnetic Fe3O4 layers and the antiferromagnetic NiO layers, with the magnetic ordering in each layer altered by the proximity to the magnetic moments in the adjacent layer. Strain and other layer-thickness effects are also evident in these magnetic layered structures. The special influence of interlayer coupling and strain on the Fe3O4 Verwey transition are discussed.

scholarly journals Revealing noncollinear magnetic ordering at the atomic scale via XMCD

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fridtjof Kielgast ◽  
Ivan Baev ◽  
Torben Beeck ◽  
Federico Pressacco ◽  
Michael Martins
Keyword(s):  
Ground State ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Atomic Scale ◽  
Angle Of Incidence ◽  
X Ray ◽  
First Time ◽  
X Ray Absorption ◽  
Magnetic Sublattices

AbstractMass-selected V and Fe monomers, as well as the heterodimer $${\text{Fe}}_1{\text{V}}_1$$ Fe 1 V 1 , were deposited on a Cu(001) surface. Their electronic and magnetic properties were investigated via X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Anisotropies in the magnetic moments of the deposited species could be examined by means of angle resolving XMCD, i.e. changing the X-ray angle of incidence. A weak adatom-substrate-coupling was found for both elements and, using group theoretical arguments, the ground state symmetries of the adatoms were determined. For the dimer, a switching from antiparallel to parallel orientation of the respective magnetic moments was observed. We show that this is due to the existence of a noncollinear spin-flop phase in the deposited dimers, which could be observed for the first time in such a small system. Making use of the two magnetic sublattices model, we were able to find the relative orientations for the dimer magnetic moments for different incidence angles.

X-Ray Diffraction Study of Rare Earth Epitaxial Structures Grown by MBE onto (111) GaAs

1989 ◽  
Vol 151 ◽  
Author(s):  
W. R. Bennett ◽  
R. F. C. Farrow ◽  
S. S. P. Parkin ◽  
E. E. Marinero
Keyword(s):  
Rare Earth ◽  
Molecular Beam Epitaxy ◽  
Rare Earth Metal ◽  
Molecular Beam ◽  
Earth Metal ◽  
Magnetic Ordering ◽  
Metal Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strain Components

ABSTRACTWe report on the new epitaxial system LaF3/Er/Dy/Er/LaF3/GaAs (111) grown by molecular beam epitaxy. X-ray diffraction studies have been used to determine the epitaxial relationships between the rare earths, the LaF3 and the substrate. Further studies of symmetric and asymmetric reflections yielded the in-plane and perpendicular strain components of the rare earth layers. Such systems may be used to probe the effects of magnetoelastic interactions and dimensionality on magnetic ordering in rare earth metal films and multilayers.

scholarly journals Gas‐source molecular‐beam epitaxy using Si2H6and GeH4and x‐ray characterization of Si1−xGex(0≤x≤0.33) alloys

1992 ◽  
Vol 71 (10) ◽  
pp. 4916-4919 ◽  
Author(s):  
S. H. Li ◽  
S. W. Chung ◽  
J. K. Rhee ◽  
P. K. Bhattacharya
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray ◽  
Gas Source

MAGNETIC AND STRUCTURAL PROPERTIES OF SOME ABa2Cu3O7−δ SUPERCONDUCTORS

1987 ◽  
Vol 01 (03n04) ◽  
pp. 989-992 ◽  
Author(s):  
M.T. Causa ◽  
S.M. Dutrús ◽  
C. Fainstein ◽  
G. Nieva ◽  
H.R. Salva ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Specific Heat ◽  
Powder Diffraction ◽  
Magnetic Moments ◽  
Superconducting Properties ◽  
X Ray ◽  
Structural Modifications

We report here normal and superconducting properties of ABa 2 Cu 3 O 7−δ (with A=Y, Gd, Dy, and Er) and of Fe doped YBa2Cu3O7−δ . Results from X-ray powder diffraction, electrical resistivity, magnetic susceptibility, ESR, and specific heat measurements are presented, leading to a characterization of the magnetic properties of these materials. The effect of structural modifications of the lattice on the superconducting properties and the relative insensitivity of Tc to the presence of magnetic moments is discussed.

Optical and X-Ray Diffraction Characterization of MBE-Grown InGaAs, InAlAs and InGaAIAs on InP

1994 ◽  
Vol 340 ◽  
Author(s):  
Z. C. Feng ◽  
S. J. Chua ◽  
A. Raman ◽  
N.N. Lim
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Molecular Beam ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Lattice Matched ◽  
Comprehensive Characterization

ABSTRACTA variety of Inl-xGaxAs, Inl-yAlyAs and Inl-x-yGaxAlyAs films have been grown on InP by molecular beam epitaxy. A comprehensive characterization was performed using Raman scattering, photoluminescence (PL), Fourier transform infrared (FTIR) spectroscopy and double crystal X-ray diffraction on these ternary and quaternary heterostructures with different compositions and growth conditions. The lattice matched and mismatched structures are studied. Our analyses show that the interface mismatch exerts an important influence on the optical properties of these heterostructures, and conversely that Raman, PL and FTIR can be used to probe the interface mismatch nondestructively.

Rare earth-rhodium-plumbides RE2Rh2Pb with RE = La–Nd, Sm, Gd and Tb

2018 ◽  
Vol 73 (12) ◽  
pp. 1015-1021 ◽  
Author(s):  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Room Temperature ◽  
Magnetic Moments ◽  
Induction Melting ◽  
Temperature Dependent ◽  
X Ray ◽  
Conduction Electrons ◽  
Paramagnetic Behavior ◽  
Arc Melting ◽  
Intergrowth Structures

AbstractThe plumbides RE2Rh2Pb (RE = La–Nd, Sm, Gd, Tb) were synthesized in sealed niobium ampoules by induction melting of the pure elements or directly via arc-melting. The characterization of the samples by X-ray powder diffraction confirmed their Mo2B2Fe-type structure (space group P4/mbm) at room temperature. The Sm2Rh1.924Pb structure was refined from single-crystal X-ray diffractometer data: a=760.02(5), c=378.20(3) pm, wR=0.0387, 292 F2 values, 13 variables. The rhodium site shows small defects. The RE2Rh2Pb plumbides are simple 1:1 intergrowth structures of AlB2 and CsCl related slabs of compositions RERh2 and REPb. The Rh2 dumbbell in the SmRh2 slab of Sm2Rh2Pb shows a Rh–Rh distance of 281 pm. Temperature-dependent magnetic susceptibility measurements of La2Rh2Pb, Pr2Rh2Pb and Nd2Rh2Pb showed that the rhodium atoms carry no localized magnetic moments. La2Rh2Pb exhibits Pauli-paramagnetic behavior induced by the conduction electrons. The ground state of the praseodymium compound is ferromagnetic below TC=3.3 K while the neodymium compound shows a transition to an antiferromagnetic state at TN=6.1 K and a metamagnetic transition at a critical field of ca. 1000 Oe.

Characterization of molecular beam epitaxy grown CdF2 layers by x‐ray diffraction and CaF2:Sm photoluminescence probe

1995 ◽  
Vol 13 (6) ◽  
pp. 2703-2708 ◽  
Author(s):  
N. S. Sokolov ◽  
N. N. Faleev ◽  
S. V. Gastev ◽  
N. L. Yakovlev ◽  
A. Izumi ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
X Ray

PHYSICAL CHARACTERIZATION OF PURE AND SUBSTITUTED TETRAGONAL LaBaCaCu3O7-δ SUPERCONDUCTOR

2001 ◽  
Vol 15 (14) ◽  
pp. 415-453 ◽  
Author(s):  
V. P. S. AWANA ◽  
A. V. NARLIKAR
Keyword(s):  
Magnetic Ordering ◽  
Superconducting Properties ◽  
Anionic Sites ◽  
X Ray ◽  
Structural Details ◽  
The Rich ◽  
Reported Data ◽  
Capacity Data ◽  
Structural Aspects

The high T c superconductor, forming the focus of the present review, presents an interesting situation where, despite its oxygen content close to 7.0, the system prefers to crystallize in tetragonal structure, as distinct from exhaustively studied orthorhombic RE:123 ( REBa 2 Cu 3 O 7, RE = rare earth) compounds. Its optimum T c is decided by the cation intermixing at various sites, unlike that in case of normal RE:123, where all cationic sites are fully occupied and fixed, leaving the anionic sites free for oxygen filling. In this, we review the rich crystal chemistry of this compound and discuss it in conjunction with its unusual superconducting properties. The article is divided in five parts: (1) first we discuss variously reported interesting finer structural details and superconductivity of pristine LaBaCaCu 3 O 7-δ (La:1113) superconductor. The La, Ba and Ca sites are found to be intermixed with respect to their nominal sites of the standard RE:123 structure. (2) We examine the structural aspects and superconductivity of La 1-x RE x BaCaCu 3 O 7 (RE = Nd, Dy, Sm and Pr). Unlike RE:123 and 124 compounds, the RE:1113 compounds form only with light rare earths such as La, Pr and Nd. Pr:1113 compound is found to be an insulator with Pr moments ordering magnetically at around 8 K, unlike at 17 K for Pr:123. (3) Studies of Pr substitution reveal that relative T c depression due to Pr in the (La,Nd) 1-x Pr x BaCaCu 3 O 7 system is less in comparison to that found for La or Nd site Pr substituted (La,Nd) 1-x Pr x Ba 2 Cu 3 O 7. (4) The results of superconductivity and structural details are reviewed for LaBaCaCu 3-x M x O 7 (M = Fe, Co, Ni, Ga and Zn) and finally (5) we summarize our conclusions. The results in terms of T c depression due to these impurities in the parent La:1113 system are seen as similar to those observed for RE:124 ( REBa 2 Cu 4 O 8) and Nd:214 ( Nd 2-x Ce x CuO 4), but are different from RE:123 and La:214. The results of structural details, superconductivity and magnetic ordering presented in the four parts for La 1-x RE x BaCaCu 3-y M y O 7 (RE = Nd, Dy, Sm, Pr with 1.0 ≥ x ≥ 0.0, and M = Fe, Co, Ni, Ga and Zn with 0.24 ≥ y ≥ 0.0 were obtained from X-ray and neutron diffraction and using AC and DC magnetic susceptibility, electrical resitivity and heat capacity data as a function of temperature. This review is mainly a consolidated work of the authors, including their collaboration from various laboratories and the reported data of other workers, all being duly acknowledged in the text.

Rare earth-rich cadmium compounds RE10TCd3 (RE=Y, Tb, Dy, Ho, Er, Tm, Lu; T=Rh, Pd, Ir, Pt) with an ordered Co2Al5-type structure

2018 ◽  
Vol 73 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Theresa Block ◽  
Steffen Klenner ◽  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Intermetallic Phases ◽  
Induction Melting ◽  
Temperature Dependent ◽  
Interatomic Distances ◽  
X Ray ◽  
Paramagnetic Behavior ◽  
Strong Covalent Bonding

AbstractEighteen new rare earth-rich intermetallic phasesRE10TCd3(RE=Y, Tb, Dy, Ho, Er, Tm, Lu;T=Rh, Pd, Ir, Pt) were obtained by induction melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. All samples were characterized by X-ray powder diffraction. The structures of four representatives were refined from single-crystal X-ray diffractometer data: ordered Co2Al5type,P63/mmc,a=951.2(1),c=962.9(2) pm,wR=0.0460, 595F2values, 20 parameters for Er10RhCd3;a=945.17(4),c=943.33(4),wR=0.0395, 582F2values, 21 parameters for Lu9.89PdCd3.11;a=964.16(6),c=974.93(6) pm,wR=0.0463, 614F2values, 21 parameters for Y10Ir1.09Cd2.91;a=955.33(3),c=974.56(3) pm,wR=0.0508, 607F2values, 22 refined parameters for Dy9.92IrCd3.08. Refinements of the occupancy parameters revealed small homogeneity ranges resulting fromRE/Cd, respectivelyT/Cd mixing. The basic building units of theRE10TCd3phases are transition metal-centeredRE6trigonal prisms (TP) that are condensed with double-pairs of emptyRE6octahedra via common triangular faces. A second type of rods is formed by slightly distortedRE3@Cd6RE6icosahedra which are condensed via Cd3triangular faces. The shortest interatomic distances occur forRE–T, compatible with strong covalent bonding interactions. Temperature dependent magnetic susceptibility measurements were performed forRE10RhCd3(RE=Dy–Tm, Lu),RE10IrCd3(RE=Er, Tm, Lu) andRE10PtCd3(RE=Y, Lu). While Y10PtCd3and Lu10TCd3(T=Rh, Ir, Pt) show Pauli paramagnetic behavior, the compounds containing paramagnetic rare earth elements show Curie-Weiss behavior (the experimental magnetic moments indicate stable trivalentRE3+) and magnetic ordering at low temperatures:TC=80.5 K for Dy10RhCd3and Neél temperatures of 42.1, 23.3, 12.6, 5.9, 10.0 K for Ho10RhCd3, Er10RhCd3, Er10IrCd3, Tm10RhCd3, Tm10IrCd3, respectively.

Fabrication and characterization of ZnMgO nanowalls grown on 4H-SiC by molecular beam epitaxy

2019 ◽  
Vol 52 (1) ◽  
pp. 168-170
Author(s):  
Mieczyslaw A. Pietrzyk ◽  
Aleksandra Wierzbicka ◽  
Marcin Stachowicz ◽  
Dawid Jarosz ◽  
Adrian Kozanecki
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optoelectronic Devices ◽  
Growth Conditions ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization

Control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic devices. This paper reports the growth conditions and structural properties of ZnMgO nanowalls grown on the Si face of 4H-SiC substrates by molecular beam epitaxy without catalysts and buffer layers. Images from scanning electron microscopy revealed that the ZnMgO nanowalls are arranged in parallel rows following the stripe morphology of the SiC surface, and their thickness is around 15 nm. The crystal quality of the structures was evaluated by X-ray diffraction measurements.

Sign in / Sign up

Export Citation Format

Share Document