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1.
Bernard Chevalier Pascal Lejay Jean Etourneau Marcus Vlasse Paul Hagenmuller 《Materials Research Bulletin》1982,17(9):1211-1220
New ternary silicides RE2Rh3Si5 (RE = Y, La, Nd, Sm, Gd, Tb, Dy, Ho, Er) have been prepared. They crystalize in the U2Co3Si5-type structure. Only the silicides containing the diamagnetic rare earths Y and La show a superconducting transition at TCr = 4.4 ± 0.2K and TCr = 2.7 ± 0.1K respectively, those with magnetic rare earths order antiferromagnetically at low temperature. 相似文献
2.
New ternary silicides have been prepared in rare earth-rhodium-silicon systems. They have the hexagonal CeCo3B2- type structure (space group ) with the general formulae RERh3Si2 (RE = Y, La, Nd, Sm, Gd, Dy, Ho, Er). Except the Y and La compounds which are diamagnetic, they are ferromagnetically ordered at low temperature. No superconductivity has been found for YRh3Si2 and LaRh3Si2 at temperatures as low as 50 mK. 相似文献
3.
Bernard Chevalier Alexandra Cole Pascal Lejay Marcus Vlasse Jean Etourneau Paul Hagenmuller Roland Georges 《Materials Research Bulletin》1982,17(2):251-258
New ternary silicides RERhSi (RE=Y, Gd, Tb, Dy, Ho, Er) have been prepared by arc melting from the elements and annealed for for several days at 800°C. Single crystal studies show these materials to be of orthorhombic symmetry and isostructural with TiNiSi (anti-PbCl2 structure). Gd, Tb and Dy compounds show a spontaneous magnetization and their ordering consists probably of a non-colinear arrangement of the moments. HoRhSi and ErRhSi order antiferromagnetically at 8K and 7.5K respectively. At 4.2K HoRhSi undergoes a metamagnetic transition above 6kOe. A field transition appears also at 4.2K for ErRhSi above 12kOe. 相似文献
4.
G. Venturini M. Méot-Meyer E. Mc Rae J.F. Marêché B. Roques 《Materials Research Bulletin》1984,19(12):1647-1652
Twenty ternary germanides, which crystallize in the Sc5Co4Si10 type, have been prepared in the RE-T-Ge systems where RE is a rare earth and T = Co, Rh, Ir: with Co, RE = Tm-Lu; with Rh, RE = Y, Gd-Lu; with Ir, RE = Gd-Lu. Lu5Rh4Ge10 and Lu5Ir4Ge10 show superconducting transitions at 2.2?1.6 K and 2.01?1.94 K respectively. 相似文献
5.
H. Barz 《Materials Research Bulletin》1980,15(10):1489-1491
A new superconducting ternary system with the formula MRu3Si2+x, where x ~ +.2 is reported. M is Y, La and Th. The superconducting transition temperatures range from 7.6 K for La to 3.5 K for Y. 相似文献
6.
New equiatomic ternary silicides MIrSi (M = Y, Ti, Zr, Hf) crystallizing with the TiNiSi-type structure (anti-PbCl2) have been prepared. Those with Y(Tcr = 2.70 K), Zr(Tcr = 2.04 K) and Hf(Tcr = 3.50 K) are the first superconducting ternary silicides having such a structure. The titanium compound has not been found to be superconducting above 1.7 K. 相似文献
7.
A new group of superconducting ternary borides has been found with the general formula MTB2, where M is Sc, Y or Lu and T is Ru or Os. The superconducting transition temperatures range from 1.3K for ScOsB2 to 10.0K for LuRuB2. Additionally, ismorphous compounds with M=Tb, Dy, Ho, Er or Tm order magnetically with critical temperatures in the range 2K to 46K. The occurrence of superconductivity and magnetism in this new ternary boride structure is discussed with respect to analogous data in MT4B4 systems. 相似文献
8.
M. Meot-Meyer G. Venturini B. MaLaman J. Steinmetz B. Roques 《Materials Research Bulletin》1984,19(9):1181-1186
New ternary stannides are reported : RE2Rh3Sn5 (RE = Y, Gd, Tb, Dy, Ho). Y2Rh3Sn5 has been studied by single - crystal X-ray diffraction analysis. Its structure is of a new type with space group Cmc21 and Z = 4 : a = 4,387(2), b = 26,212(4), , Dx = 8,71 Mgm?3, μ(AgKα) = 17 mm?1, F(000) = 1851, R = 0,045 for 478 independant reflexions (Rw = 0,046). This structure is characterized by a tridimensionnal lattice of RhSn covalent bonds with two very different sites for yttrium. Y2Rh3Sn5 is diamagnetic and semimetallic according to its electrical properties. 相似文献
9.
RExLu2-x
O3:Eu3+ (RE = Y, Gd) nanophosphors with x = 0.4, 1.0, and 1.6 were synthesized using rare-earth salicylate coordination polymers as precursors for the luminescent species RExLu2-x
O3:Eu3+ (RE = Y, Gd) composed of polyethylene glycol both as a dispersing medium and fuel. Their particle sizes were around 100 nm as determined by scanning electron microscopy and x-ray diffraction.__________From Neorganicheskie Materialy, Vol. 41, No. 6, 2005, pp. 706–710.Original English Text Copyright © 2005 by Zhou, Yan.This article was submitted by the authors in English. 相似文献
10.
Hiroyuki Sasakura Yoshiya Akagi Masashi Tanaka Shigeki Tsukui Motoaki Adachi 《Journal of Superconductivity and Novel Magnetism》2013,26(3):633-638
A new family of the Pb-based layered cuprate with the 1222 structure has been synthesized in the (Pb,S)Sr2(RE,Ce)2Cu2O z (RE=Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, and Y) system. The almost-single phase samples are obtained for x=0.25 and y=1.0 in the composition of (Pb1?x S x )Sr2(RE2?y Ce y )Cu2O z . Each of the samples has the crystal structure with a tetragonal symmetry. Both of the lattice parameters a and c are decreasing with the decrease of the ionic radius of RE element. Among these samples, the sample with RE=Er has the smallest resistivity in the whole temperature range and the slope of the resistivity versus temperature is the most gentle. Despite annealing under O2 atmosphere at high-pressure of 121 atm, this sample is a semiconductor with the transport process characteristics of three-dimensional variable range hopping conduction. Then the samples of RE=Er with smaller y are investigated for the composition of (Pb0.75S0.25)Sr2(RE2?y Ce y )Cu2O z , the sample with y=0.4 is found to show an onset of resistivity drop phenomenon at about 11 K with the decrease of temperature. Moreover, we also discover that the samples of RE=Ho with y=0.4 show an onset of the resistivity dropping at over 20 K and zero resistivity at 13 K. From these results, the present (Pb0.75S0.25)Sr2(RE2?y Ce y )Cu2O z system is considered to be a new family of the Pb-based superconducting cuprates with the 1222 structure. 相似文献
11.
Wang Xian Zhong Wee Lam Ng B. Chevalier J. Etourneau P. Hagenmuller 《Materials Research Bulletin》1985,20(10):1229-1238
New silicides have been prepared in ternary systems: thorium-transition element (T = Co, Ni, Pt)-silicon. With cobalt compounds ThCoxSi2?x (0 ? x ? 1) a structural change occurs with the sequence α 1bThSi2(tetr.) → β 1bThSi2(hex) →α 1b ThSi2(tetr.) as x increases. It has been clearly shown that ThPtSi is isostructural with LaPtSi (i.e. of ordered α 1bThSi2 type). However structure refinement from X-ray powder measurements is not conclusive to decide whether Si and T atoms are ordered or disordered in ThTSi (T = Co, Rh, Ir, Ni) compounds of α 1bThSi2 type. ThNiSi, ThPtSi and the cobalt poor and rich compounds have clearly been found to be superconducting above 2K. 相似文献
12.
P. Lejay I. Higashi B. Chevalier J. Etourneau P. Hagenmuller 《Materials Research Bulletin》1984,19(1):115-123
New superconducting ternary silicides LaRhSi3 and LaIrSi3 have been prepared by arc melting from the elements and annealing for ten days at 900°C. A single crystal study shows these materials to be of tetragonal symmetry and isostructural with BaPtSn3. Their superconducting transition temperature which depends strongly on stoichiometry and thermal treatment occurs between 1.9 K and 2.7 K. The structures have been compared to those of the superconducting compounds LaRh2Si2 and La2Rh3Si5. The occurence of superconductivity in these materials seems to be related to the presence of similar coordination polyhedra for Rh or Ir and Si atoms. 相似文献
13.
Ugur Topal Mustafa Akdogan Husnu Ozkan 《Journal of Superconductivity and Novel Magnetism》2011,24(7):2099-2102
This paper presents the synthesis and characterization of the new superconducting compounds with nominal composition, RE3Ba5Cu8O18, RE=Y, Sm and Nd. The onset critical temperatures of the present samples are 97.5, 97 and 95 K for the RE=Y, Sm and Nd, respectively.
The first two values are the highest for the RE–Ba–Cu–O superconductors recorded to date. The RE3Ba5Cu8O18 samples crystallize in the orthorhombic system, with increased unit cell volume as Sm and Nd replace the element Y. 相似文献
14.
AC magneitic susceptibilities measured between 1 and 4.2 K are reported for a series of rare earth bromate hydrates, RE(BrO3)3 · 9H2O, for the rare earths Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, and Yb. Results for Pr, Tb, Dy, and Er are in good agreement with a previous determination. New results are reported for Nd, Sm, Gd, Ho, and Yb, some of which show interesting differences from the structurally similar rare earth ethylsulfates and anhydrous trichlorides. 相似文献
15.
Victor Quezada-Novoa Hatem M. Titi Francisco Yarur Villanueva Mark W. B. Wilson Ashlee J. Howarth 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(36):2302173
The tetratopic linker, 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4TBAPy) along with rare-earth (RE) ions is used for the synthesis of 9 isostructures of a metal–organic framework (MOF) with shp topology, named RE-CU-10 (RE = Y(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), and Lu(III)). The synthesis of each RE-CU-10 analogue requires different reaction conditions to achieve phase pure products. Single crystal X-ray diffraction indicates the presence of a RE9-cluster in Y- to Tm-CU-10, while a RE11-cluster is observed for Yb- and Lu-CU-10. The photooxidation performance of RE-CU-10 analogues is evaluated, observing competition between linker-to-metal energy transfer versus the generation of singlet oxygen. The singlet oxygen produced is used to detoxify a mustard gas simulant 2-chloroethylethyl sulfide, with half-lives ranging from 4.0 to 5.8 min, some of the fastest reported to date using UV-irradiation and < 1 mol% catalyst, in methanol under O2 saturation. 相似文献
16.
The structural properties of a new group of ternary silicides in the system M-Ru-Si (M = Y, La, Th and RE) have been investigated. The structure is presented as determined from X-ray powder diffraction. 相似文献
17.
《Materials Research Bulletin》1987,22(6):829-840
Ternary chalcogenides LiLnS2, LiLnSe2, NaLnS2, and NaLnSe2 (Ln-La, Ce, Nd, Sm, Gd, Tb, Dy, Ho, Er, or Y) were prepared by heating the mixtures of elements. DTA(differential thermal analysis) measurements showed the first order transitions at high temperatures above 600 °C in LiLnS2 (Ln=Dy, Ho, Er, Y), LiLnSe2 (Ln=Gd to Er), NaNdS2, and NaCeSe2, which are considered order-disorder transitions between a NaCl and an α-NaFeO2 structure. This is consistent with X-ray diffraction measurements. Magnetic susceptibility measurements revealed that all the lanthanides ions are in trivalent state. 相似文献
18.
The preparation of a new series of heptavalent rhenium compounds of Ln3ReO8 type (Ln = rare earths) is described. The crystals are orthorombic for Ln = La (space groups Ccmm, Ccm21 or Cc2m) and Ln = Pr, …, Gd (space group B2212), face centered cubic of fluorite type for Ln = Tb, …, Lu and Y. 相似文献
19.
The phase relations of the ternary systems SiC–Si3N4–R2O3 (R = Gd and Y) have been investigated by XRD phase analyses of the hot-pressed samples from SiC, Si3N4, and R2O3 powders. Their subsolidus phase diagrams were presented. In situ SiO2 impurity in the powders always led to form some oxygen-richer rare-earth siliconoxynitrides and extend the ternary systems
to the quaternary systems of SiC–Si3N4–SiO2–R2O3 (R = Gd, Y). Within these systems all rare-earth siliconoxynitrides coexist with SiC. The phase diagrams of the quaternary
systems of SiC–Si3N4–SiO2–R2O3 (R = Gd, Y) were established, in which the subsolidus diagram of Si3N4–SiO2–Gd2O3 system was first reported. 相似文献
20.
不同稀土元素掺杂对钛酸钡陶瓷导电性的影响 总被引:4,自引:1,他引:3
采用溶胶-凝胶法制备了14种稀土掺杂的BaTiO3超细粉体(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Yb,Lu),用一般陶瓷工艺将这些超细粉体分别烧成了14种稀土掺杂的BaTiO3陶瓷,测得了这些陶瓷体的电阻率并对Eu和Yb掺杂的BaTiO3陶瓷成绝缘体的原因进行了初步讨论。 相似文献