TY - JOUR
T1 - Low-Energy Magnetic Excitations in the Antiferromagnetically Ordered State of an Incipient Heavy-Electron Compound UP as Studied by 31P NMR
AU - Takagi, Shigeru
PY - 1994/1/1
Y1 - 1994/1/1
N2 - The microscopic magnetic properties of UP with the cubic NaCl-type structure have been investigated by 31P NMR in the magnetically ordered state. 1 /T1 is extraordinarily large in the single-g type-I phase (T0 ≅& 22.5 K< T< TN≅ 122 K), and shows about two orders of magnitude abrupt decrease through the single-Q ↔ double-Q phase transition at T0. Below about 4K in the double-Q type-I phase (T<T0), 1/T1 shows a Korringa-like temperature-dependence, which corresponds qualitatively to a 5f-derived γ term in the specific heat. We discuss this behavior as a clear indication of the existence of 5f-derived very-low-energy magnetic excitations even in the ordered state, and an incipient heavy-electron character of the compound is concluded. We also present a simple qualitative model of a system of exchange-coupled Kondo impurities under internal exchange (or molecular) field in order to discuss the origin of these excitations.
AB - The microscopic magnetic properties of UP with the cubic NaCl-type structure have been investigated by 31P NMR in the magnetically ordered state. 1 /T1 is extraordinarily large in the single-g type-I phase (T0 ≅& 22.5 K< T< TN≅ 122 K), and shows about two orders of magnitude abrupt decrease through the single-Q ↔ double-Q phase transition at T0. Below about 4K in the double-Q type-I phase (T<T0), 1/T1 shows a Korringa-like temperature-dependence, which corresponds qualitatively to a 5f-derived γ term in the specific heat. We discuss this behavior as a clear indication of the existence of 5f-derived very-low-energy magnetic excitations even in the ordered state, and an incipient heavy-electron character of the compound is concluded. We also present a simple qualitative model of a system of exchange-coupled Kondo impurities under internal exchange (or molecular) field in order to discuss the origin of these excitations.
KW - NMR
KW - UP
KW - heavy electron
KW - low-energy magnetic excitation
KW - nuclear magnetic relaxation
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U2 - 10.1143/JPSJ.63.4604
DO - 10.1143/JPSJ.63.4604
M3 - Article
AN - SCOPUS:77952768199
VL - 63
SP - 4604
EP - 4611
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 12
ER -