A New Class of Oxide Superconductor (Nd, Ce, Sr)2CuO4

1989 ◽  
Vol 156 ◽  
Author(s):  
E. Takayama-Muromachi
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry ◽  
Superconducting Phase ◽  
Type Structure ◽  
Oxide Superconductor ◽  
New Class ◽  
System 2 ◽  
New Type ◽  
System 1 ◽  
Tetragonal Cell

ABSTRACTSince the discovery of the high-Tc superconductor in the La-Ba-Cu-O system [1], a great deal of experimental and theoretical effort have been made to clarify the nature of the Cu-based oxides. In order to elucidate mechanism of the high-Tc superconductivity, discovery of a new type of superconductor is no doubt of great importance. Recently, Akimitsu et al. found a new oxide superconductor in the Nd-Ce-Sr-Cu-O system [2]. Soon after their discovery, the superconducting phase was isolated and identified [3]. It has a tetragonal cell with space group P4/nmm and has a structure closely related to but different from the K2NiF4− or T'-Nd2CuO4− -type structure. Although, Tc of the Nd-Ce-Sr-Cu oxide is not so high (ca. 20 K) compared with the 1–2–3 or Bi(Tl)-based superconductors, it has aroused interest widely due to a very simple crystal structure. In this article, I will discuss superconductivity and crystal chemistry of the Nd-Ce-Sr-Cu oxide. Also, various compounds isostructural to it will be presented.

Dy3Co6Sn5 – a New Stannide with an Ordered La3Al11 Type Structure

1995 ◽  
Vol 50 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Single Crystal ◽  
Crystal Chemistry ◽  
Title Compound ◽  
Type Structure ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Arc Melting ◽  
New Type

The title compound has been obtained by arc-melting of the elemental components and subsequent annealing at 800 °C. It crystallizes in the orthorhombic space group Immm, a = 430.3(1), b = 1235.0(2), c = 967.6(3) pm, V = 0.5142(2) nm3, Z = 2. The structure has been determined from single-crystal X-ray data and refined to R = 0.0181 for 747 F2 values and 28 variables. It is of a new type and can be described as a ternary ordered version of the binary La3Al11-type structure. Dy3Co6Sn5 is built up from DyCo2Sn2 and DyCo2Sn slabs with ThCr2Si2 and Cu3Au-like atomic arrangements, respectively. Its crystal chemistry is compared with that of structurally related rare earth transition metal gallides.

Ternary Rare Earth Metal Gold Stannides and Indides with Ordered U3Si2 and Zr3Al2-Type Structure

1994 ◽  
Vol 49 (11) ◽  
pp. 1525-1530 ◽  
Author(s):  
Rainer Pöttgen
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Crystal Chemistry ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Type Structure ◽  
X Ray ◽  
Arc Melting ◽  
Cscl Type

The new ternary stannides RE2Au2Sn (RE = Gd, Tb) and indides RE2Au2In (RE = Y, Gd-Tm, Lu) were synthesized by arc-melting of the elemental components and subsequent annealing at 800 °C. While Gd2Au2Sn, Tb2Au2Sn and the indides with RE = Y, Gd-Er crystallize in the ordered U3Si2 structure, Tm2Au2In and Lu2Au2In adopt the ordered Zr3Al2 structure, respectively. The crystal structure of Dy2Au2In was refined from single-crystal X- ray data: P4/mbm, Z = 2, a = 784.1(1) pm, c = 373.9(1) pm, V = 0.2299 nm3 and R = 0.028 for 342 F2 values and 12 variables. The tin (indium) atoms in these compounds occupy [RE8] square prisms and the gold atoms are surrounded by [RE6] trigonal prisms. These fragments are derived from the AlB2 and CsCl-type structures. The crystal chemistry of these com­pounds is briefly discussed.

STRUCTURAL STUDIES ON THE SUPERCONDUCTING PHASE Bi4Sr4Ca2Cu4O2−δ

1988 ◽  
Vol 02 (02) ◽  
pp. 551-557 ◽  
Author(s):  
YOUQI TANG ◽  
BINGXIONG LIN ◽  
XIANGMIAO ZHENG ◽  
WENJIE ZHU ◽  
YUFEN ZHANG ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Superconducting Phase ◽  
Structural Studies ◽  
Homogeneous Sample ◽  
New Class ◽  
Structural Work ◽  
Xrd Method

Very recently H. Maeda et al.1 reported a high Tc superconducting material of the composition BiSrCaCu2O χ that makes a feature of containing no rare earth metal. We are interested in the structural and chemical aspects of this new class of materials.2 We have prepared a homogeneous sample for the superconducting phase in the Bi-Sr-Ca-Cu-O system, and have determined its crystal structure by powder XRD method. At a very late stage we noticed the structural work by a Bellcore group.3 Fortunately our work has quite a number of distinguishable features.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

ChemInform Abstract: Crystal Structure of Pb2SbS2I3, and Re-Examination of the Crystal Chemistry within the Group of (Pb/Sn/Sb) Chalcogeno-Iodides.

ChemInform ◽  
2008 ◽  
Vol 39 (1) ◽  
Author(s):  
Charlotte Doussier ◽  
Yves Moelo ◽  
Philippe Leone ◽  
Alain Meerschaut ◽  
Michel Evain
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry

A 2-D Zn(II) coordination polymer based on 4,5-imidazoledicarboxylate and bis(benzimidazole) ligands: synthesis, crystal structure and fluorescence properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xinzhao Xia ◽  
Lixian Xia ◽  
Geng Zhang ◽  
Yuxuan Jiang ◽  
Fugang Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Zigzag Chain ◽  
Supramolecular Framework ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hydrogen Bond Interaction ◽  
X Ray ◽  
New Type ◽  
Solid State Fluorescence

Abstract In this work, a new type of zinc(II) coordination polymer {[Zn(HIDC)(BBM)0.5]·H2O} n (Zn-CP) was synthesized using 4,5-imidazoledicarboxylic acid (H3IDC) and 2,2-(1,4-butanediyl)bis-1,3-benzimidazole (BBM) under hydrothermal conditions. Its structure has been characterized by infrared spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The Zn(II) ion is linked by the HIDC2− ligand to form a zigzag chain by chelating and bridging, and then linked by BBM to form a layered network structure. Adjacent layers are further connected by hydrogen bond interaction to form a 3-D supramolecular framework. The solid-state fluorescence performance of Zn-CP shows that compared with free H3IDC ligand, its fluorescence intensity is significantly enhanced.

scholarly journals Milk Production, Body Weight, Body Condition Score, Activity, and Rumination of Organic Dairy Cattle Grazing Two Different Pasture Systems Incorporating Cool- and Warm-Season Forages

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 264
Author(s):  
Kathryn E. Ritz ◽  
Bradley J. Heins ◽  
Roger D. Moon ◽  
Craig C. Sheaffer ◽  
Sharon L. Weyers
Keyword(s):  
Body Weight ◽  
Milk Production ◽  
Body Condition Score ◽  
Warm Season ◽  
Cool Season ◽  
Organic Dairy ◽  
Condition Score ◽  
Annual Grasses ◽  
System 2 ◽  
System 1

Organic dairy cows were used to evaluate the effect of two organic pasture production systems (temperate grass species and warm-season annual grasses and cool-season annuals compared with temperate grasses only) across two grazing seasons (May to October of 2014 and 2015) on milk production, milk components (fat, protein, milk urea nitrogen (MUN), somatic cell score (SCS)), body weight, body condition score (BCS), and activity and rumination (min/day). Cows were assigned to two pasture systems across the grazing season at an organic research dairy in Morris, Minnesota. Pasture System 1 was cool-season perennials (CSP) and Pasture System 2 was a combination of System 1 and warm-season grasses and cool-season annuals. System 1 and System 2 cows had similar milk production (14.7 and 14.8 kg d−1), fat percentage (3.92% vs. 3.80%), protein percentage (3.21% vs. 3.17%), MUN (12.5 and 11.5 mg dL−1), and SCS (4.05 and 4.07), respectively. Cows in System 1 had greater daily rumination (530 min/day) compared to cows in System 2 (470 min/day). In summary, warm-season annual grasses may be incorporated into grazing systems for pastured dairy cattle.

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