Magnetic order and weak ferromagnetic transition in Gd2CuO4

2000 ◽  
Vol 87 (9) ◽  
pp. 5911-5913 ◽  
Author(s):  
J. Mira ◽  
J. Rivas ◽  
A. Butera ◽  
L. B. Steren ◽  
J. M. Garcı́a-Beneytez ◽  
...  
Keyword(s):  
Magnetic Order ◽  
Ferromagnetic Transition ◽  
Weak Ferromagnetic

CRYSTALLINE STRUCTURE AND PHYSICAL PROPERTIES OF UCo2Al3

2004 ◽  
Vol 18 (30) ◽  
pp. 3905-3914
Author(s):  
E. VERDÍN ◽  
R. ESCUDERO
Keyword(s):  
Intermetallic Compound ◽  
Physical Properties ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Heavy Fermion ◽  
Ferromagnetic Transition ◽  
Crystallographic Characteristics ◽  
Heavy Fermion Behavior ◽  
Small Single Crystal ◽  
Weak Ferromagnetic

Some intermetallic compounds which contain uranium or cerium present heavy fermion characteristics. Take, for example, in the UM 2 Al 3 ( M = Pd , Ni ) family, superconductivity and magnetism coexist and present heavy fermion behavior. This work presents the crystallographic characteristics and physical properties of a new compound of this family; the intermetallic compound UCo 2 Al 3. Our initial crystallographic studies performed in a small single crystal show that the structure is hexagonal and similar to the UNi 2 Al 3 and UPd 2 Al 3 parent compounds. The space group is P6/mmm with a=5.125 Å and c=4.167 Å crystalline parameters. Measurements of resistivity and magnetization performed on the single crystal reveal that the compound is not superconducting when measured at about 1.8 K. The compound is highly anisotropic and features related to Kondo-like behavior are observed. A weak ferromagnetic transition is observed at a temperature of about 20 K.

A Neutron Powder Diffraction Study of the Ferromagnetic Superconductor RuSr2(Gd1.3Ce0.7)Cu2O10-σ

2000 ◽  
Vol 659 ◽  
Author(s):  
Christopher S. Knee ◽  
Mark T. Weller
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Magnetic Order ◽  
Oxygen Deficiency ◽  
Structural Response ◽  
Rietveld Analysis ◽  
Neutron Powder Diffraction ◽  
Ferromagnetic Transition ◽  
Copper Site ◽  
Fluorite Type

ABSTRACTThe temperature dependence of the crystal structure of the ferromagnetic superconductor RuSr2(160Gd1.3Ce0.7)Cu2O10-σ, which orders magnetically at TC ∼ 180 K and exhibits a Tc ∼ 30 K, has been investigated by time-of-flight neutron powder diffraction. In this system superconductivity is believed to occur in the CuO2 layers while the magnetic order is associated with the Ru moments. The tetragonal structure evolves from that of YBa2Cu3O7-σ by inserting a fluorite-type Gd1.3Ce0.7O2 layer instead of the Y ion and replacing the chain copper site with RuO6 octahedra. Rietveld analysis reveals that the basal oxygens of the RuO6 octahedra are displaced within the xy-plane to accommodate physically reasonable Ru-O in-plane bonds. These displacements are consistent with rotations of the octahedra by ∼ 15° around the c-axis. Data were collected at 40 K, 70 K, 100 K, 130 K, 150 K, 170 K 190 K and 230 K but no large structural response associated with the ferromagnetic transition is observed. A small level of oxygen deficiency within the (Gd/Ce)2O2−x, fluorite layer (x = 0.1) is detected leading to a refined stoichiometry of RuSr2(Gd1.3Ce0.7)Cu2O9.9.

scholarly journals Long-range magnetic order in real icosahedral quasicrystals

2021 ◽  
Author(s):  
Ryuji Tamura ◽  
Asuka Ishikawa ◽  
Shintaro Suzuki ◽  
Akihiro Kotajima ◽  
Yujiro Tanaka ◽  
...  
Keyword(s):  
Specific Heat ◽  
Long Range ◽  
Magnetic Order ◽  
Global Symmetry ◽  
Icosahedral Symmetry ◽  
Ferromagnetic Transition ◽  
Range Magnetic Order ◽  
Magnetic Orders ◽  
Icosahedral Quasicrystals ◽  
Long Range Magnetic Order

Abstract Quasicrystals (QCs), first discovered in 1984, generally do not exhibit long-range magnetic order. Here, we report on long-range magnetic order in the real icosahedral quasicrystals (i QCs) Au–Ga–Gd and Au–Ga–Tb. The Au65Ga20Gd15 i QC exhibits a ferromagnetic transition at TC = 23 K, manifested as a sharp anomaly in both magnetic-susceptibility and specific-heat measurements. Quick magnetic saturation to almost the full moment (7μB/Gd3+) is observed under 100 Oe at 2 K. This is the first observation of long-range magnetic order in a real quasicrystal, in contrast to the spin-glass-like behaviours observed for the other magnetic quasicrystals found to date. Moreover, when Gd is replaced by Tb, i.e. for the Au65Ga20Tb15 i QC, a ferromagnetic behaviour is still retained with TC = 16 K. Although the sharp anomaly in the specific heat observed for the Au65Ga20Gd15 i QC is significantly broadened upon Tb substitution, neutron-diffraction experiments clearly show the marked development of magnetic Bragg peaks below TC, indicating long-range magnetic order for the Au65Ga20Tb15 i QC also. Our findings can contribute to the further investigation of exotic magnetic orders formed on real quasiperiodic lattices with unprecedented highest global symmetry, i.e. icosahedral symmetry.

scholarly journals Magnetoresistive study of the antiferromagnetic–weak ferromagnetic transition in single-crystal La2CuO4+δ

2004 ◽  
Vol 30 (5) ◽  
pp. 411-416 ◽  
Author(s):  
B. I. Belevtsev ◽  
N. V. Dalakova ◽  
V. N. Savitsky ◽  
A. S. Panfilov ◽  
I. S. Braude ◽  
...  
Keyword(s):  
Single Crystal ◽  
Ferromagnetic Transition ◽  
Weak Ferromagnetic

Magnetization Mössbauer Effect and Superconductivity in Fe2Te3

1974 ◽  
Vol 52 (18) ◽  
pp. 1800-1804 ◽  
Author(s):  
Erika Hermon ◽  
W. B. Muir ◽  
J. Quaroni ◽  
R. C. Sweet
Keyword(s):  
Liquid Helium ◽  
Temperature Variation ◽  
Density Of States ◽  
Mössbauer Effect ◽  
Meissner Effect ◽  
Internal Field ◽  
Ferromagnetic Transition ◽  
Superconducting Transition ◽  
Mossbauer Effect ◽  
Weak Ferromagnetic

The magnetization and Mössbauer effect in Fe2Te3 have been measured between liquid helium temperatures and 300 K and the Meissner effect has been studied between 1.7 and 4.2 K. Both the Mössbauer effect and the magnetization indicate that Fe2Te3 undergoes a weak ferromagnetic transition at about 10 K and has an internal field of 11 kOe at the lowest temperatures. The superconducting transition predicted by Atzeri and Mula was not observed. Above 10 K the temperature variation of the susceptibility is probably a reflection of the energy dependence of the d band density of states on the Pauli spin susceptibility of the material.

Dependence of weak-ferromagnetic transition in single crystals on the filling ratio

2007 ◽  
Vol 310 (2) ◽  
pp. e298-e300 ◽  
Author(s):  
T. Ikeno ◽  
A. Mitsuda ◽  
T. Kuwai ◽  
T. Mizushima ◽  
Y. Isikawa ◽  
...  
Keyword(s):  
Single Crystals ◽  
Filling Ratio ◽  
Ferromagnetic Transition ◽  
Weak Ferromagnetic

Magnetic order and phase transitions in Fe50Pt50–xRhx

2015 ◽  
Vol 48 (4) ◽  
pp. 1142-1158
Author(s):  
Jochen Fenske ◽  
Dieter Lott ◽  
Elena V. Tartakovskaya ◽  
Hwachol Lee ◽  
Patrick R. LeClair ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Neutron Diffraction ◽  
Magnetic Order ◽  
Magnetic Transition ◽  
Antiferromagnetic Order ◽  
Ferromagnetic Transition ◽  
Temperature Dependent ◽  
Out Of Plane ◽  
Plane Direction ◽  
Bulk System

Polarized and unpolarized neutron diffraction techniques have been applied to study the temperature-dependent magnetic and structural properties of four 200 nm-thick Fe50Pt50−xRhxfilms withx= 5,x= 10,x= 17.5 andx= 25. Similar to the bulk system, an antiferromagnetic to ferromagnetic transition can be found in the films with decreasing Rh concentration. The application of structure factor calculations enables one to determine the microscopic magnetic configuration of the different films as a function of temperature and Rh concentration. The developed models indicate a magnetic transition from a dominant antiferromagnetic order in the out-of-plane direction to a dominant ferromagnetic order in the in-plane direction with decreasing Rh concentration. The different magnetic configurations can theoretically be described by a phenomenological model which includes a two-ion and a one-ion interaction Hamiltonian term with different temperature dependencies of the anisotropy constants.

Sign in / Sign up

Export Citation Format

Share Document