http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Sb NQR Study of the Filled Skutterudite CeFe4Sb12 Synthesized under High Pressure
Ko-ichi Magishi,,Masahiro Takahashi,Takahito Saito,Kuniyuki Koyama,Hitoshi Sugawara,Takashi Saito,Sho Tatsuoka,Kenya Tanaka,Hideyuki Sato 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3
We report the results of Sb nuclear quadrupole resonance (NQR) measurements on the filledskutterudite CeFe4Sb12 synthesized under high pressure (HP) and compare them with those forthe sample synthesized under ambient pressure (AP) to understand the influence of the Ce-sitefilling fraction. The NQR spectra for the HP sample are much sharper than those for the APsample, suggesting that the Ce filling fraction is higher. Also, the nuclear spin-lattice relaxationrate 1/T1 follows an exponential decrease 1/T1 ∝ exp(−Δ/kBT), with the gap being Δ/kB = 270K at temperatures above 100 K, which is larger than that for the AP sample. This result suggeststhat the c-f hybridization is enhanced by increasing the Ce-site filling fraction.
Magnetic Memory in a Ceramic YBCO Superconductor Composed of Sub-micron-size Grains
Hiroyuki Deguchi,Takuya Ashida,Mitsuhiro Syudo,Masaki Mito,Seishi Takagi,Makoto Hagiwara,Kuniyuki Koyama 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12
The ceramic YBa2Cu4O8 (YBCO) composed of sub-micron-size grains is considered as a randomJosephson-coupled network of 0 and junctions and shows successive phase transitions. The firsttransition occurs inside each grain at Tc1 = 81 K, and the second transition occurs among thegrains at Tc2 = 47 K. A magnetic glass behavior similar to those of spin-glasses is observed attemperatures below Tc2. The memory phenomena are investigated by recording the zero-fieldcooledand thermoremanent magnetizations measured on heating after the cooling process witha halt at Ts = 41 K. Memory effects of the halt are imprinted in the system when the sampleis re-heated. In the case without a field switch at Ts, the influence of the halt is confined to anarrow temperature region near Ts whereas the memory effect of the halt employing a field switchis extended over a wide temperature region below Ts. The results suggest that chiral-glass orderingoccurs at Tc2 in the ceramic YBCO.