TY - JOUR
T1 - Magnetic properties
T2 - Mössbauer, x-ray absorption spectroscopy, and specific-heat studies (M=Ta, In, Nb, Nb+Ga) compounds
AU - Asaf, U.
AU - Felner, I.
AU - Schmitt, D.
AU - Barbara, B.
AU - Godart, C.
AU - Alleno, E.
PY - 1996
Y1 - 1996
N2 - We have investigated (Formula presented)(Formula presented)M(Formula presented)(Formula presented)(Formula presented) (z=9 or 10) materials (M=Ta, In, and Nb+Ga) by complementary experimental techniques. All materials studied are not superconducting. Magnetic susceptibility studies for M=Ta reveal one magnetic anomaly at 23 K and irreversibility phenomena at higher temperatures. The presence of 0.5% (Formula presented) dramatically affects the positions of the anomalies, and Mössbauer spectroscopy studies (MS) reveal that the Cu(2) sites are magnetically ordered below (Formula presented)(Cu)=130 K. This low (Formula presented)(Cu) obtained is discussed. No specific heat anomaly was observed at 23 K, suggesting that the Pr sublattice does not order magnetically, and the anomalies in the susceptibility originate from the Cu moments. No anomalies in the susceptibility curves are found for M=In and Nb+Ga compounds. However, MS indicate that for the mixed compound, the Cu sites are magnetically ordered at low temperatures. The magnetic behavior of M=Ta is compared to similar systems with two anomalies for M=Nb at 11 and 52 K, and three anomalies for M=Ga at 12, 52, and 94 K. X-ray absorption spectroscopy (XAS) indicates that in all materials studied, the Pr has a mixed valence close to 3. The Pr valence does not change with temperature.
AB - We have investigated (Formula presented)(Formula presented)M(Formula presented)(Formula presented)(Formula presented) (z=9 or 10) materials (M=Ta, In, and Nb+Ga) by complementary experimental techniques. All materials studied are not superconducting. Magnetic susceptibility studies for M=Ta reveal one magnetic anomaly at 23 K and irreversibility phenomena at higher temperatures. The presence of 0.5% (Formula presented) dramatically affects the positions of the anomalies, and Mössbauer spectroscopy studies (MS) reveal that the Cu(2) sites are magnetically ordered below (Formula presented)(Cu)=130 K. This low (Formula presented)(Cu) obtained is discussed. No specific heat anomaly was observed at 23 K, suggesting that the Pr sublattice does not order magnetically, and the anomalies in the susceptibility originate from the Cu moments. No anomalies in the susceptibility curves are found for M=In and Nb+Ga compounds. However, MS indicate that for the mixed compound, the Cu sites are magnetically ordered at low temperatures. The magnetic behavior of M=Ta is compared to similar systems with two anomalies for M=Nb at 11 and 52 K, and three anomalies for M=Ga at 12, 52, and 94 K. X-ray absorption spectroscopy (XAS) indicates that in all materials studied, the Pr has a mixed valence close to 3. The Pr valence does not change with temperature.
UR - http://www.scopus.com/inward/record.url?scp=0005298326&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.54.16160
DO - 10.1103/PhysRevB.54.16160
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AN - SCOPUS:0005298326
SN - 1098-0121
VL - 54
SP - 16160
EP - 16167
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 22
ER -