Mössbauer Spectroscopic Analysis of Nd2Fe14B/α-Fe Hard Magnetic Nanocomposites

2011 ◽  
Vol 170 ◽  
pp. 154-159
Author(s):  
Bozidar Cekić ◽  
Valentin Ivanovski ◽  
Mirela Maria Codescu ◽  
Ana Umićević ◽  
Tanja Barudzija ◽  
...  
Keyword(s):  
Rare Earth ◽  
Melt Spinning ◽  
Room Temperature ◽  
Spectroscopic Analysis ◽  
Magnetic Hyperfine Field ◽  
Exchange Interactions ◽  
Magnetic Nanocomposites ◽  
Magnetic Intermetallics ◽  
Paramagnetic Doublet ◽  
Fe Sites

Among novel magnetic intermetallics based on rare earth-transition compounds, the Nd2Fe14B/α-Fe isotropic nanocomposites have been obtained by recrystallization from an amorphous phase, prepared by melt spinning. For variable 5 wt.% Fe and 10 wt.% Fe contents we recorded transmission 57Fe Mössbauer spectra at the room temperature, hardened of the α-Fe phase by exchange interactions. The spectra have been analyzed in terms of ten Zeeman sextets and one paramagnetic doublet related to the Nd1.1Fe4B4 phase. One sextet corresponds to the α-Fe phase, whereas others are attributed to six non-equivalent Fe sites in the Nd2Fe14B structure, namely 16k1, 16k2, 8j1, 8j2, 4c, and 4e. The three remaining sextets belong to the Fe3B structure with three inequivalent Fe sites FeI(8g), FeII(8g) and FeIII(8g). All relevant parameters for both nanocomposites: the magnetic hyperfine field, the isomer shift and the quadrupole splitting are determined for each of these sites.

Dispersoid Modification of Ti3Al-Nb Alloys

1985 ◽  
Vol 58 ◽  
Author(s):  
R. G. Rowe ◽  
J. A. Sutliff ◽  
E. F. Koch
Keyword(s):  
Fracture Toughness ◽  
Rare Earth ◽  
Titanium Aluminide ◽  
Melt Spinning ◽  
Room Temperature ◽  
Beta Transus ◽  
Processing Conditions ◽  
Room Temperature Ductility ◽  
Rapidly Solidified ◽  
Titanium Aluminide Alloys

ABSTRACTTitanium aluminide alloys with matrix compositions of essentially Ti3Al plus 0, 5, 7.5, and 10 a/o Nb and with and without rare earth elements for dispersoid formation were prepared. The alloys were rapidly solidified by melt spinning. Ribbon was consolidated by HIP and extrusion at temperatures below the beta transus temperatures of the alloys. The effects of processing conditions and dispersoid additions on room temperature ductility and fracture toughness were studied.

scholarly journals Self-assembly induced luminescence of Eu3+-complexes and application in bioimaging

2021 ◽  
Author(s):  
Ping-Ru Su ◽  
Tao Wang ◽  
Pan-Pan Zhou ◽  
Xiao-Xi Yang ◽  
Xiao-Xia Feng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Luminescence Intensity ◽  
Self Assembly ◽  
Room Temperature ◽  
Molecular Motion ◽  
Proof Of Concept ◽  
Room Temperature Phosphorescence ◽  
New Strategy ◽  
Size Controlled

Abstract Design and engineering of highly efficient emitting materials with assembly-induced luminescence, such as room temperature phosphorescence (RTP) and aggregation-induced emission (AIE), have stimulated extensive efforts. Here, we propose a new strategy to obtain size-controlled Eu3+-complex nanoparticles (Eu-NPs) with self-assembly induced luminescence (SAIL) characteristics without encapsulation or hybridization. Compared with previous RTP or AIE materials, the SAIL phenomena of increased luminescence intensity and lifetime in aqueous solution for the proposed Eu-NPs are due to the combined effect of self-assembly in confining the molecular motion and shielding the water quenching. As a proof of concept, we also show that this system can be further applied in bioimaging, temperature measurement and HClO sensing. The SAIL activity of the rare-earth (RE) system proposed here offers a further step forward on the roadmap for the development of RE light conversion systems and their integration in bioimaging and therapy applications.

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

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.

scholarly journals Structure and Properties of Ln2MoO6 Oxymolybdates (Ln = La, Pr, Nd) Doped with Magnesium

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Ekaterina Orlova ◽  
Elena Kharitonova ◽  
Timofei Sorokin ◽  
Alexander Antipin ◽  
Nataliya Novikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Infrared Spectroscopy ◽  
Room Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Spectroscopy Data ◽  
Structure And Properties ◽  
Hygroscopic Properties ◽  
Thermogravimetric Studies ◽  
Mg Doped

The literature data and the results obtained by the authors on the study of the structure and properties of a series of polycrystalline and single-crystal samples of pure and Mg-doped oxymolybdates Ln2MoO6 (Ln = La, Pr, Nd) are analyzed. Presumably, the high-temperature phase I41/acd of Nd2MoO6 single crystals is retained at room temperature. The reason for the loss of the center of symmetry in the structures of La2MoO6 and Pr2MoO6 and the transition to the space group I4¯c2 is the displacement of oxygen atoms along the twofold diagonal axes. In all structures, Mg cations are localized near the positions of the Mo atoms, and the splitting of the positions of the atoms of rare-earth elements is found. Thermogravimetric studies, as well as infrared spectroscopy data for hydrated samples of Ln2MoO6 (Ln = La, Pr, Nd), pure and with an impurity of Mg, confirm their hygroscopic properties.

Microstructural Studies of NiCoMnIn Magnetic Shape Memory Ribbons

2013 ◽  
Vol 738-739 ◽  
pp. 436-440 ◽  
Author(s):  
Krystian Prusik ◽  
Katarzyna Bałdys ◽  
Danuta Stróż ◽  
Tomasz Goryczka ◽  
Józef Lelątko
Keyword(s):  
Melt Spinning ◽  
Room Temperature ◽  
Parent Phase ◽  
Magnetic Shape Memory ◽  
Melt Spun ◽  
Columnar Grains ◽  
Ebsd Technique ◽  
Microstructural Studies ◽  
Melt Spinning Technique ◽  
Scanning Electron

In present paper two ribbons of the Ni44Co6Mn36In14 (at.%) were prepared under different melt-spinning technique conditions. Microstructure of the ribbons was studied by scanning electron microscopy (SEM). Depending on the liquid ejection overpressure two types of ribbons microstructures were observed. Ribbon T1 for which ejection overpressure was 1.5 bar showed typical melt-spun ribbon microstructure consisting of a top layer of small equi-axial grains and columnar grains below. For T2 ribbon (ejection overpressure 0.2 bar) only a small fraction of the columnar grains were observed. Structure analysis of the ribbons performed by XRD showed that at room temperature both ribbons have B2 parent phase superstructure. No gamma phase precipitates were observed. In order to determine the orientation of the grains the EBSD technique was applied.

Influence of Modulation Wavelength Induced Order on the Physical Properties of Nb/Rare Earth Superlattices

1984 ◽  
Vol 37 ◽  
Author(s):  
L. H. Greene ◽  
W. L. Feldmann ◽  
J. M. Rowell ◽  
B. Batlogg ◽  
R. Hull ◽  
...  
Keyword(s):  
Rare Earth ◽  
Room Temperature ◽  
Room Temperature Resistivity ◽  
Residual Resistance ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Residual Resistance Ratio ◽  
Temperature Resistivity ◽  
Modulation Wavelength

AbstractWe report the observation of a higher degree of preferred crystalline orientation in Nb/rare earth superlattices for modulation wavelengths in the range of 200 Å to 500 Å than that exhibited by single component films. All films and multilayers are sputter deposited onto room temperature sapphire substrates. Electronic transport measurements also show that the residual resistance ratio is higher and the room temperature resistivity is lower than for multilayers of either greater or lower periodicities. Transmission electron micrographs (TEM) showing excellent layering, grain size comparable to the layer thickness, and evidence of some degree of epitaxy are presented.

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