Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
SR study of CeRhIn
under applied pressureHeffner, R.*; 後神 達郎*; Andreica, D.*; 大石 一城*; 髭本 亘; 伊藤 孝; Amato, A.*; Spehling, J.*; Klauss, H. H.*; Bauer, E. D.*; et al.
Journal of Physics; Conference Series, 225, p.012011_1 - 012011_6, 2010/06
被引用回数：1 パーセンタイル：50.20(Physics, Applied)At ambient pressure CeRhIn is an incommensurate antiferromagnet with Neel temperature 
= 3.8 K. The application of pressure reduces and yields (1) a state in which AFM coexists with superconductivity, and then (2) a superconducting state in the absence of AFM. We report transverse-field muon spin relaxation (SR) measurements at pressures 2.07 and 2.26 GPa in the pure superconducting state of single-crystalline CeRhIn. SR is sensitive to the local field distribution produced by the vortex lattice in a mixed superconducting state, allowing a measurement of the magnetic field penetration depth 
. We measured 
for applied field along the 
-axis as a function of temperature 
, and find 
(0) = 372(5) nm and 338(6) nm for 
= 2.07 GPa and 2.26 GPa, respectively. The -dependence of the superfluid density 
was found to be 
with 
= 1.9(2).
SRから眺めたCeCo(In,Cd)の磁性大石 一城; Heffner, R. H.; MacDougall, G. J.*; 伊藤 孝; 髭本 亘; Luke, G. M.*; Amato, A.*; Nieuwenhuys, G.*; Spehling, J.*; Klauss, H. H.*; et al.
no journal, ,
最近、CeCoInのInサイトをCdで置換することにより、
が減少し反強磁性秩序が出現することが報告された。NMR実験によると、Cd置換量10%の試料では磁気秩序と超伝導秩序の共存が示唆され、さらにこの磁性は置換したCd近傍で出現していることが示された。一方、同じ組成の試料による中性子実験では、
以下で
=(1/2, 1/2, 1/2)の反強磁性秩序を形成することが示された。われわれは本系の磁性に関する微視的知見、特に磁気成分の体積分率を調べるため、Cd置換量3%, 10%及び15%の単結晶試料を用いて零磁場中でミュオンスピン緩和測定を行った。その結果、10%及び15%Cd置換した試料において、以下で磁気秩序形成に伴うミュオンスピン回転を観測し、磁性成分の体積分率はほぼ100%であることを観測した。また10%の試料では、の前後で回転周波数の温度依存性に大きな変化はなかった。一方、超伝導のみを示す3%Cd置換試料では、核双極子磁場による緩和以外は観測されず、時間反転対称性が破れていないことを示した。
probed by SR大石 一城; Heffner, R. H.; Spehling, J.*; MacDougall, G. J.*; 伊藤 孝; 髭本 亘; Amato, A.*; Nieuwenhuys, G.*; Klauss, H. H.*; Luke, G. M.*; et al.
no journal, ,
The heavy fermion superconductor CeCoIn has the highest critical temperature ( = 2.3 K) of the Ce-based 115 materials. Recently, it has been found that Cd substitution on the In site drives the system towards antiferromagnetism (AFM). Recent NMR studies suggest that the magnetism develops locally in the vicinity of the Cd atoms. Neutron scattering experiments on a sample with a nominal Cd concentration of 10% showed the coexistence of superconductivity and AFM. The AFM order develops below with the commensurate wave vector = (1/2, 1/2, 1/2) and the magnetic intensity did not increase below . We have performed SR measurements on single crystalline samples of Cd-doped CeCoIn at nominal Cd concentrations of 3%, 10% and 15% in order to further elucidate the magnetic and superconducting properties of CeCo(In,Cd). The crystallographic axis was aligned along the initial muon spin for both zero and in applied fields. In contrast to neutron scattering, SR can independently measure both the magnitude of the local field and the magnetic volume fraction. Muon spin precession signal was observed below in both the 10% and 15% Cd-doped samples, with different fractions of precession asymmetry. No magnetic signal in zero applied field was observed for the 3% sample.
