High-Frequency, High-Field EPR; Magnetic Susceptibility; and X-ray Studies on a Ferromagnetic Heterometallic Complex of Diethanolamine (H2L), [Cu4(NH3)4(HL)4][CdBr4]Br2·3dmf·H2O

2005 ◽  
Vol 44 (2) ◽  
pp. 206-216 ◽  
Author(s):  
Elena A. Buvaylo ◽  
Vladimir N. Kokozay ◽  
Olga Yu. Vassilyeva ◽  
Brian W. Skelton ◽  
Julia Jezierska ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
High Frequency ◽  
High Field ◽  
Heterometallic Complex ◽  
X Ray

Er5Re2C7, Tm5Re2C7, and Lu5Re2C7 with Sc5Re2C7 Type, and Yb2ReC2 with Pr2ReC2 Type Structures

1997 ◽  
Vol 52 (2) ◽  
pp. 231-236 ◽  
Author(s):  
R. Pöttgen ◽  
K. H. Wachtmann ◽  
W. Jeitschko ◽  
A. Lang ◽  
T. Ebel
Keyword(s):  
Magnetic Susceptibility ◽  
Bond Length ◽  
High Frequency ◽  
Annealing Process ◽  
Type Structure ◽  
The Other ◽  
Variable Parameters ◽  
X Ray ◽  
Arc Melting ◽  
Structure Factors

Abstract Er5Re2C7, Tm5Re2C7, and Lu5Re2C7 were prepared by arc-melting of the elemental components and subsequent annealing at 800 °C. Er5Re2C7 forms only after the annealing process, whereas the other two carbides were already present in the as cast samples. They crystallize with a Sc5Re2C7 type structure, which was refined from single-crystal X-ray data of Lu5Re2C7: Cmmm, a = 791.44(5), b = 1418.08(8), c = 332.79(2) pm, Z = 2, R = 0.037 for 544 structure factors and 21 variable parameters. The structure contains linear centrosymmetric C3 units with a C-C bond length of 133(2) pm and isolated carbon atoms in octahedral coordination of four lutetium and two rhenium atoms. The rhenium atoms within the two-dimensionally infinite polymeric sheets [Re2C4]n are electronically saturated as is indicated by the diamagnetism and the semiconductivity of this carbide. Yb2ReC2 was prepared by reacting the elements in a sealed tantalum tube with a high-frequency furnace. It crystallizes with a Pr2ReC2 type structure: Pnma, a = 645.91(6), b = 498.64(6), and c = 966.05(6) pm. Magnetic susceptibility measurements indicate the ytterbium atoms to be trivalent in this compound.

Ternary aurides RE4Mg3Au10 (RE = La, Ce, Pr) and RE4Cd3Au10 (RE = Y, La–Nd, Sm, Gd–Dy) – ordering variants of the Zr7Ni10 type

2015 ◽  
Vol 70 (12) ◽  
pp. 889-896 ◽  
Author(s):  
Michael Johnscher ◽  
Theresa Block ◽  
Oliver Niehaus ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Specific Heat ◽  
Coordination Number ◽  
High Frequency ◽  
Two Dimensional ◽  
Muffle Furnace ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Gold Compounds

AbstractThe intermetallic gold compounds RE4Mg3Au10 (RE = La, Ce, Pr) and RE4Cd3Au10 (RE = Y, La–Nd, Sm, Gd–Dy) were obtained from the elements through high-frequency melting in sealed niobium tubes and subsequent annealing in a muffle furnace. The new aurides crystallize with the Ca4In3Au10-type structure. They were characterized through Guinier powder patterns. The structures of Pr4.46Cd2.54Au10 and Tb4.38Cd2.62Au10 were refined from single crystal X-ray diffractometer data: Cmce, a = 1396.73(6), b = 1009.38(3), c = 1019.51(3) pm, wR2 = 0.0423, 1281 F2 values, 47 variables for Pr4.46Cd2.54Au10 and a = 1362.68(3), b = 995.52(4), c = 1003.79(3) pm, wR2 = 0.0381, 1594 F2 values, F2 47 variables for Tb4.38Cd2.62Au10. The 8e sites of both crystals show substantial Cd/Pr respectively Cd/Tb mixing, indicating small homogeneity ranges for all RE4+xMg3–xAu10 and RE4+xCd3–xAu10 aurides. The gold atoms in these aurides form a pronounced two-dimensional substructure (275–327 pm Au–Au in Pr4.46Cd2.54Au10) which encages the Mg1/Cd1 (coordination number 8) and RE2 (coordination number 11) atoms. These blocks are separated by the Mg2/Cd2 and RE1 atoms with an intergrowth of Mg2/Cd2@Au8 and RE1@Au10 polyhedra. Temperature dependent magnetic susceptibility and specific heat measurements of Tb4Cd3Au10 have shown antiferromagnetic ordering at a Néel temperature of 12(1) K.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

High-field soft-x-ray dichroism of a hard ferrimagnet with easy-plane anisotropy

2021 ◽  
Vol 104 (6) ◽  
Author(s):  
Sh. Yamamoto ◽  
D. I. Gorbunov ◽  
I. F. Diaz-Ortega ◽  
A. Miyata ◽  
T. Kihara ◽  
...  
Keyword(s):  
High Field ◽  
Easy Plane ◽  
X Ray ◽  
Plane Anisotropy

scholarly journals Sintering, Microstructure, and Dielectric Properties of Copper Borates for High Frequency LTCC Applications

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
High Frequency ◽  
Ceramic Materials ◽  
Sintering Behavior ◽  
Terahertz Time Domain Spectroscopy ◽  
Very High Frequency ◽  
X Ray ◽  
Low Dielectric ◽  
Very High

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.

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