ChemInform Abstract: Single Crystalline and Rare Earth Substituted La2RuO5Investigated by X-Ray Diffraction and EXAFS Spectroscopy.

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.

Download Full-text

High-pressure synthesis of REB5O8(OH)2 (RE = Ho, Er, Tm)

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0180 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Michael Zoller ◽

Hubert Huppertz

Keyword(s):

High Pressure ◽

Rare Earth ◽

Ir Spectroscopy ◽

Earth Metal ◽

Monoclinic Space Group ◽

X Ray Diffraction ◽

X Ray ◽

Structure Solution ◽

Pressure Synthesis ◽

The Rare Earth

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.

Download Full-text

Temperature-induced structural phase transitions in RERhSn (RE = Y, Gd-Tm, Lu)

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2021-2008 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Simon Engelbert ◽

Rolf-Dieter Hoffmann ◽

Jutta Kösters ◽

Steffen Klenner ◽

Rainer Pöttgen

Keyword(s):

Rare Earth ◽

Phase Transitions ◽

Driving Force ◽

Room Temperature ◽

Structural Phase ◽

Structural Phase Transitions ◽

Line Broadening ◽

X Ray Diffraction ◽

Temperature Dependent ◽

X Ray

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

Download Full-text

Effect of the Neodymium Content on Mechanical Properties of the Electro-Brush Plated Nano-Al2O3/Ni Composite Coating

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.525-526.277 ◽

2012 ◽

Vol 525-526 ◽

pp. 277-280

Author(s):

Guo Jin ◽

Xiu Fang Cui ◽

Er Bao Liu ◽

Qing Fen Li

Keyword(s):

Mechanical Properties ◽

Rare Earth ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Composite Coating ◽

Nanoindentation Test ◽

X Ray Diffraction ◽

X Ray ◽

Small Cracks ◽

Scanning Electron

The effect of the neodymium content on mechanical properties of the electro-brush plated nanoAl2O3/Ni composite coating was investigated in this paper. The microstructure and phase structure were studied with scanning electron microscope (SEM) and X-ray diffraction (XRD). The hardness and abrasion properties of several coatings with different neodymium content were studied by nanoindentation test and friction / wear experiment. Results show that the coatings are much finer and more compact when the neodymium was added, and the hardness and abrasion property of the coatings with neodymium were improved obviously. Besides, the small cracks conduced by the upgrowth stress in the coatings were ameliorated when the rare earth neodymium was added. The improvement mechanism was further discussed.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-151-277 ◽

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.

Download Full-text

Rare-earth crystal chemistry of thalénite-(Y) from different environments

Mineralogical Magazine ◽

10.1180/minmag.2017.081.044 ◽

2018 ◽

Vol 82 (2) ◽

pp. 313-327

Author(s):

Markus B. Raschke ◽

Evan J. D. Anderson ◽

Jason Van Fosson ◽

Julien M. Allaz ◽

Joseph R. Smyth ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Spatial Scales ◽

Structure Refinement ◽

X Ray Diffraction ◽

Heavy Rare Earth ◽

Heavy Rare Earth Element ◽

X Ray ◽

Golden Horn

ABSTRACTThalénite-(Y), ideally Y3Si3O10F, is a heavy-rare-earth-rich silicate phase occurring in granite pegmatites that may help to illustrate rare-earth element (REE) chemistry and behaviour in natural systems. The crystal structure and mineral chemistry of thalénite-(Y) were analysed by electron microprobe analysis, X-ray diffraction and micro-Raman spectroscopy from a new locality in the peralkaline granite of the Golden Horn batholith, Okanogan County, Washington State, USA, in comparison with new analyses from the White Cloud pegmatite in the Pikes Peak batholith, Colorado, USA. The Golden Horn thalénite-(Y) occurs as late-stage sub-millimetre euhedral bladed transparent crystals in small miarolitic cavities in an arfvedsonite-bearing biotite granite. It exhibits growth zoning with distinct heavy-rare-earth element (HREE) vs. light-rare-earth element (LREE) enriched zones. The White Cloud thalénite-(Y) occurs in two distinct anhedral and botryoidal crystal habits of mostly homogenous composition. In addition, minor secondary thalénite-(Y) is recognized by its distinct Yb-rich composition (up to 0.8 atoms per formula unit (apfu) Yb). Single-crystal X-ray diffraction analysis and structure refinement reveals Y-site ordering with preferential HREE occupation of Y2 vs. Y1 and Y3 REE sites. Chondrite normalization shows continuous enrichment of HREE in White Cloud thalénite-(Y), in contrast to Golden Horn thalénite-(Y) with a slight depletion of the heaviest REE (Tm, Yb and Lu). The results suggest a hydrothermal origin of the Golden Horn miarolitic thalénite-(Y), compared to a combination of both primary magmatic followed by hydrothermal processes responsible for the multiple generations over a range of spatial scales in White Cloud thalénite-(Y).

Download Full-text

Crystal structure characterization and electronic structure of a rare-earth-containing Zintl phase in the Yb–Al–Sb family: Yb3AlSb3

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229621005192 ◽

2021 ◽

Vol 77 (6) ◽

Author(s):

Rongqing Shang ◽

An T. Nguyen ◽

Allan He ◽

Susan M. Kauzlarich

Keyword(s):

Crystal Structure ◽

Electronic Structure ◽

Rare Earth ◽

Electronic Structure Calculations ◽

Structure Characterization ◽

Charge Balance ◽

X Ray Diffraction ◽

Zintl Phase ◽

X Ray ◽

Structure Calculations

A rare-earth-containing compound, ytterbium aluminium antimonide, Yb3AlSb3 (Ca3AlAs3-type structure), has been successfully synthesized within the Yb–Al–Sb system through flux methods. According to the Zintl formalism, this structure is nominally made up of (Yb2+)3[(Al1−)(1b – Sb2−)2(2b – Sb1−)], where 1b and 2b indicate 1-bonded and 2-bonded, respectively, and Al is treated as part of the covalent anionic network. The crystal structure features infinite corner-sharing AlSb4 tetrahedra, [AlSb2Sb2/2]6−, with Yb2+ cations residing between the tetrahedra to provide charge balance. Herein, the synthetic conditions, the crystal structure determined from single-crystal X-ray diffraction data, and electronic structure calculations are reported.

Download Full-text

Intermetallic REPtZn Compounds with TiNiSi-type Structure

Zeitschrift für Naturforschung B ◽

10.1515/znb-2011-0703 ◽

2011 ◽

Vol 66 (7) ◽

pp. 671-676 ◽

Cited By ~ 1

Author(s):

Trinath Mishra ◽

Rainer Pöttgen

Keyword(s):

Rare Earth ◽

Single Crystal ◽

Coordination Number ◽

High Frequency ◽

Three Dimensional ◽

Type Structure ◽

Rare Earth Compounds ◽

Crystal Data ◽

X Ray Diffraction ◽

X Ray

The equiatomic rare earth compounds REPtZn (RE = Y, Pr, Nd, Gd-Tm) were synthesized from the elements in sealed tantalum tubes by high-frequency melting at 1500 K followed by annealing at 1120 K and quenching. The samples were characterized by powder X-ray diffraction. The structures of four crystals were refined from single-crystal diffractometer data: TiNiSi type, Pnma, a = 707.1(1), b = 430.0(1), c = 812.4(1) pm, wR2 = 0.066, 602 F2, 21 variables for PrPt1.056Zn0.944; a = 695.2(1), b = 419.9(1), c = 804.8(1) pm, wR2 = 0.041, 522 F2, 21 variables for GdPt0.941Zn1.059; a = 688.2(1), b = 408.1(1), c = 812.5(1) pm, wR2 = 0.041, 497 F2, 22 variables for HoPt1.055Zn0.945; a = 686.9(1), b = 407.8(1), c = 810.4(1) pm, wR2 = 0.061, 779 F2, 20 variables for ErPtZn. The single-crystal data indicate small homogeneity ranges REPt1±xZn1±x. The platinum and zinc atoms build up three-dimensional [PtZn] networks (265 - 269 pm Pt-Zn in ErPtZn) in which the erbium atoms fill cages with coordination number 16 (6 Pt + 6 Zn + 4 Er). Bonding of the erbium atoms to the [PtZn] network proceeds via shorter RE-Pt distances, i. e. 288 - 293 pm in ErPtZn.

Download Full-text

Mn-Induced Thermal Stability of L10 Phase in Fept Magnetic Nanoscale Ribbons

Nanomaterials ◽

10.3390/nano10071278 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1278

Author(s):

Alina Daniela Crisan ◽

Aurel Leca ◽

Dan Pantelica ◽

Ioan Dan ◽

Ovidiu Crisan

Keyword(s):

Rare Earth ◽

Single Phase ◽

Permanent Magnets ◽

Magnetic Hysteresis ◽

Ternary Alloys ◽

Large Temperature ◽

Nominal Composition ◽

X Ray Diffraction ◽

X Ray ◽

Operation Conditions

Magnetic nanoscale materials exhibiting the L10 tetragonal phase such as FePt or ternary alloys derived from FePt show most promising magnetic properties as a novel class of rare earth free permanent magnets with high operating temperature. A granular alloy derived from binary FePt with low Pt content and the addition of Mn with the nominal composition Fe57Mn8Pt35 has been synthesized in the shape of melt-spun ribbons and subsequently annealed at 600 °C and 700 °C for promoting the formation of single phase, L10 tetragonal, hard magnetic phase. Proton-induced X-ray emission spectroscopy PIXE has been utilized for checking the compositional effect of Mn addition. Structural properties were analyzed using X-ray diffraction and diffractograms were analyzed using full profile Rietveld-type analysis with MAUD (Materials Analysis Using Diffraction) software. By using temperature-dependent synchrotron X-ray diffraction, the disorder–order phase transformation and the stability of the hard magnetic L10 phase were monitored over a large temperature range (50–800 °C). A large interval of structural stability of the L10 phase was observed and this stability was interpreted in terms of higher ordering of the L10 phase promoted by the Mn addition. It was moreover found that both crystal growth and unit cell expansion are inhibited, up to the highest temperature investigated (800 °C), proving thus that the Mn addition stabilizes the formed L10 structure further. Magnetic hysteresis loops confirmed structural data, revealing a strong coercive field for a sample wherein single phase, hard, magnetic tetragonal L10 exists. These findings open good perspectives for use as nanocomposite, rare earth free magnets, working in extreme operation conditions.

Download Full-text