A comparative three-dimensional neutron depolarization study on RCrO4 oxides (R=Y, Er, Tm, Yb)

Three-dimensional neutron depolarization experiments have been performed on RCrO4 (R=Y, Er, Tm, Yb) powder samples in order to gain insight into their magnetic domain structure in the submicrometer range. The temperature evolution of both the average domain size and the net magnetization of each compound has been studied for different applied magnetic fields. The largest average domain size at zero external magnetic field was found in YbCrO4. The effect of an applied magnetic field on the magnetic domain structure is relatively small in ErCrO4 and TmCrO4, when compared to YCrO4 and YbCrO4 where the average domain size even surpasses the average particle size determined by Scanning Electron Microscopy studies.</p

Evidence for an antiferromagnetic component in the magnetic structure of ZrZn2

Zero-field muon spin rotation experiments provide evidence for an antiferromagnetic component in the magnetic structure of the intermetallics ZrZn2.Comment: 5 pages, 2 figure

Absence of zero field muon spin relaxation induced by superconductivity in the B phase of UPt3_3

We present muon spin relaxation measurements performed on crystals of the heavy fermion superconductor UPt$_3$. In zero applied field, contrary to a previous report, we do not observe an increase of the internal magnetic field in the lower superconducting phase (the B phase). Our result gives an experimental upper bound of the magnetic field that could be associated with the superconducting state.Comment: 4 pages, REVTeX 3.0, 2 PostScript figure

Magnetic properties of rare earth iron compounds

Applied Science

MÖSSBAUER STUDY OF THE TERNARY SYSTEM Ho(Fe, Co)2

On décrit des mesures de champ magnétique hyperfin et d'éclatement quadrupolaire dans les composés intermétalliques Ho(Fe1-xCox)2. Le champ magnétique hyperfin augmente d'abord avec la concentration en cobalt et atteint un maximum pour x = 0,35 environ. Pour des concentrations de cobalt plus élevées le champ hyperfin diminue. Cependant si l'atome de fer n'a que des atomes de cobalt comme proches et seconds voisins, un champ effectif de 188 kOe est déterminé à T = 20 K, ce qui représente 84 % du champ mesuré dans HoFe2 pur. L'éclatement quadrupolaire observé augmente avec x dans tout le domaine de concentration. Cet effet peut être expliqué par une diminution du champ d'anisotropie dans ces composés.Magnetic hyperfine field and electric quadrupole splitting measurements in the intermetallic compounds Ho(Fe1-xCox)2 are reported. The magnetic hyperfine field first increases with Co-concentration and reaches a maximum at approximately x = 0.35. For higher Co-concentrations the hyperfine field decreases. However for an Fe-atom with only Co-atoms as nearest neighbours and next nearest neighbours an effective field of 188 kOe is determined at T = 20 K, which is 84 % of the field in pure HoFe2. The observed electric quadrupole splitting is increasing with x over the whole concentration region. This effect can be explained by a decrease of the anisotropy field in these compounds

MAGNETIC AND ELECTRIC PROPERTIES OF R2Fe17 COMPOUNDS STUDIED BY MEANS OF THE MÖSSBAUER EFFECT

Les propriétés magnétiques et électriques des composés R2Fe17 (R = terre rare, yttrium ou thorium) ont été étudiées à l'aide de l'effet Mössbauer. Dans la région magnétiquement ordonnée, tous ces composés intermétalliques, sauf Tm2Fe17, présentent une anisotropie dans le plan de base. En dessous de 72 K l'anisotropie magnétique de Tm2Fe17 est parallèle à l'axe c.The magnetic and electric properties of the R2Fe17 compounds (R = rare earth, yttrium, or thorium) have been studied by using the Mössbauer effect. In the magnetically ordered state all these intermetallic compounds except for Tm2Fe17 have a basal plane anisotropy. This last compound has a c-axis anisotropy at 4 K and most likely an a-axis anisotropy at 80 K