Low-energy Ce spin excitations in CeFeAsO and
CeFeAsO 0.84 F 0.16
Low-energy Ce spin excitations in CeFeAsO and
CeFeAsO 0.84 F 0.16
Shi-liang LI (李世亮),Dao-xin
YAO (姚道新),Yi-ming QIU (邱义铭),Hye Jung KANG,E. W. CARLSON,Jiang-ping
HU (胡江平),Gen-fu
CHEN (陈根富),Nan-lin
WANG (王楠林),Peng-cheng DAI (戴鹏程),
Abstract：We use inelastic neutron scattering to study the low-energy spin excitations of polycrystalline samples of nonsuperconducting CeFeAsO and superconducting CeFeAsO0.84F0.16. Two sharp dispersionless modes are found at 0.85 and 1.16 meV in CeFeAsO below the Ce antiferromagnetic (AF) ordering temperature of . On warming to above , these two modes become one broad dispersionless mode that disappears just above the Fe ordering temperature . For superconducting CeFeAsO0.84F0.16, where Fe static AF order is suppressed, we find a weakly dispersive mode center at 0.4 meV that may arise from short-range Ce–Ce exchange interactions. Using a Heisenberg model, we simulate powder-averaged Ce spin wave excitations. Our results show that we need both Ce spin wave and crystal electric field excitations to account for the whole spectra of low-energy spin excitations.
. Low-energy Ce spin excitations in CeFeAsO and
CeFeAsO 0.84 F 0.16[J]. Front. Phys. , 2010, 5(2): 161-165.
Shi-liang LI (李世亮), Dao-xin
YAO (姚道新), Yi-ming QIU (邱义铭), Hye Jung KANG, E. W. CARLSON, Jiang-ping
HU (胡江平), Gen-fu
CHEN (陈根富), Nan-lin
WANG (王楠林), Peng-cheng DAI (戴鹏程), . Low-energy Ce spin excitations in CeFeAsO and
CeFeAsO 0.84 F 0.16. Front. Phys. , 2010, 5(2): 161-165.
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!["Graphic"]("..\images\22\23\f1\79\hcm0000143793.html.graphics/HML40084.png.gif")
. On warming to above !["Graphic"]("..\images\22\23\f1\79\hcm0000143793.html.graphics/HML40085.png.gif")
, these two modes become one broad dispersionless mode that disappears just above the Fe ordering temperature !["Graphic"]("..\images\22\23\f1\79\hcm0000143793.html.graphics/HML40086.png.gif")
. For superconducting CeFeAsO0.84F0.16, where Fe static AF order is suppressed, we find a weakly dispersive mode center at 0.4 meV that may arise from short-range Ce–Ce exchange interactions. Using a Heisenberg model, we simulate powder-averaged Ce spin wave excitations. Our results show that we need both Ce spin wave and crystal electric field excitations to account for the whole spectra of low-energy spin excitations.