Magnetic Properties of Ce_n+1Co_3n+5B_2n (n = 0, 1, 2, and 3) compounds investigated by ⁵⁹Co NMR

详细信息    查看全文

• 作者：Kenji Shimizu^a ; ¹ ; ^{kshimizutoyama@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Kei Kakiuchi^a ; ² ; Tadaei Ito^b ; ¹ ; ^{itoh@mail.tohoku-gakuin.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; Hideaki Ido^c ; ¹ ; ^{ido@mail.tohoku-gakuin.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：CeCo5 ; CeCo4B ; Ce3Co11B4 ; Ce2Co7B3 ; orbital moment ; spin-echo ; hyperfine field
• 刊名：Physics Procedia
• 出版年：2015
• 出版时间：2015
• 年：2015
• 卷：75
• 期：Complete
• 页码：853-860
• 全文大小：243 K

文摘

We have performed ⁵⁹Co spin-echo NMR measurements on Ce_n+1Co_3n+5B_2n (n = 0, 1, 2, 3) at T= 1.4 K. The NMR spectra corresponding to the inequivalent crystallographic sites were obtained. The resonance frequencies of the 2c-Co have been observed in the range 60-80 MHz, and those of the 6i-Co(6i₁-Co) around 32 MHz. In addition to the zero-field spectra, the field-swept spectra from non-magnetic Co have also been observed for Ce₃Co₁₁B₄ and Ce₂Co₇B₃. These spectra arise from the 3g-Co in Ce₃Co₁₁B₄ and the 6i₂-Co in Ce₂Co₇B₃. From the Co hyperfine field analysis, the Co magnetic moments at the inequivalent crystallographic sites are estimated. Magnitude of the spin moment for the 2c-Co is estimated to be <1.2 μ_B for Ce_n+1Co_3n+5B_2n (n = 0, 1, 2, 3), and to be about 0.4 μ_B for the 6i₁-Co in Ce₃Co₁₁B₄ and Ce₂Co₇B₃, while the orbital moment of the 2c-Co varies from <0.3 μ_B in CeCo₅ to <0.1 μ_B in Ce₂Co₇B₃, and those for the 3g-Co and 6i₁-Co are found to be 0.08 and 0.01 μ_B, respectively. The Co magnetic moments are found to be strongly influenced by the crystallographic environment around the Co site.