Abstract
We found evidence that two successive antiferromagnetic orderings of a rare earth cuprate NdCu2O4 (nonstandard monoclinic structure with magnetic Cu(1) and nonmagnetic Cu(2) sites) are strongly coupled with phonon mode anomalies. The nuclear quadrupole resonance frequency of 63,65Cu on the Cu(2) site shows a step decrease below each of the ordering temperatures TN1 ∼ 20 K and TN2 ∼ 10 K, that originates from changes in the symmetry of the charge distribution on the surrounding lattice. In the Raman spectrum, the shift of a phonon mode near 300 cm-1 displays an anomalous temperature dependence, which suggests a hardening of the lattice below TN1 and a softening below T N2. The Cu2+ spins on the Cu(1) site order antiferromagnetically below TN1, and the complex magnetic behavior is ascribed to the variations in the exchange interactions between the Cu(1) spins and in the paramagnetic spin polarization of Nd3+ below T N2.
| Original language | English |
|---|---|
| Pages (from-to) | 2076-2081 |
| Number of pages | 6 |
| Journal | Journal of the Physical Society of Japan |
| Volume | 74 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2005 Jul |
| Externally published | Yes |
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Keywords
- Antiferromagnetic ordering
- NdCuO
- NMR
- Phonon anomaly
- Raman
ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Antiferromagnetic ordering coupled with phonon mode anomalies in rare-earth cuprate NdCu2O4, probed by nuclear quadrupole resonance and raman spectroscopy. / Wada, Shinji; Sugiata, Hiroshi; Sawai, Daisuke; Mito, Takeshi; Osada, Minoru; Fisher, Robert A.; Phillips, Norman E.; Luce, Jeanne L.; Stacy, Angelica M.
In: Journal of the Physical Society of Japan, Vol. 74, No. 7, 07.2005, p. 2076-2081.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Antiferromagnetic ordering coupled with phonon mode anomalies in rare-earth cuprate NdCu2O4, probed by nuclear quadrupole resonance and raman spectroscopy
AU - Wada, Shinji
AU - Sugiata, Hiroshi
AU - Sawai, Daisuke
AU - Mito, Takeshi
AU - Osada, Minoru
AU - Fisher, Robert A.
AU - Phillips, Norman E.
AU - Luce, Jeanne L.
AU - Stacy, Angelica M.
PY - 2005/7
Y1 - 2005/7
N2 - We found evidence that two successive antiferromagnetic orderings of a rare earth cuprate NdCu2O4 (nonstandard monoclinic structure with magnetic Cu(1) and nonmagnetic Cu(2) sites) are strongly coupled with phonon mode anomalies. The nuclear quadrupole resonance frequency of 63,65Cu on the Cu(2) site shows a step decrease below each of the ordering temperatures TN1 ∼ 20 K and TN2 ∼ 10 K, that originates from changes in the symmetry of the charge distribution on the surrounding lattice. In the Raman spectrum, the shift of a phonon mode near 300 cm-1 displays an anomalous temperature dependence, which suggests a hardening of the lattice below TN1 and a softening below T N2. The Cu2+ spins on the Cu(1) site order antiferromagnetically below TN1, and the complex magnetic behavior is ascribed to the variations in the exchange interactions between the Cu(1) spins and in the paramagnetic spin polarization of Nd3+ below T N2.
AB - We found evidence that two successive antiferromagnetic orderings of a rare earth cuprate NdCu2O4 (nonstandard monoclinic structure with magnetic Cu(1) and nonmagnetic Cu(2) sites) are strongly coupled with phonon mode anomalies. The nuclear quadrupole resonance frequency of 63,65Cu on the Cu(2) site shows a step decrease below each of the ordering temperatures TN1 ∼ 20 K and TN2 ∼ 10 K, that originates from changes in the symmetry of the charge distribution on the surrounding lattice. In the Raman spectrum, the shift of a phonon mode near 300 cm-1 displays an anomalous temperature dependence, which suggests a hardening of the lattice below TN1 and a softening below T N2. The Cu2+ spins on the Cu(1) site order antiferromagnetically below TN1, and the complex magnetic behavior is ascribed to the variations in the exchange interactions between the Cu(1) spins and in the paramagnetic spin polarization of Nd3+ below T N2.
KW - Antiferromagnetic ordering
KW - NdCuO
KW - NMR
KW - Phonon anomaly
KW - Raman
UR - http://www.scopus.com/inward/record.url?scp=24644496757&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=24644496757&partnerID=8YFLogxK
U2 - 10.1143/JPSJ.74.2076
DO - 10.1143/JPSJ.74.2076
M3 - Article
AN - SCOPUS:24644496757
VL - 74
SP - 2076
EP - 2081
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 7
ER -