Now showing items 1-12 of 12

    • Anisotropic neutron spin resonance in underdoped superconducting NaFe1−xCoxAs 

      Zhang, Chenglin; Song, Yu; Regnault, L.-P.; Su, Yixi; Enderle, M.; Kulda, J.; Tan, Guotai; Sims, Zachary C.; Egami, Takeshi; Si, Qimiao; Dai, Pengcheng (2014)
      We use polarized inelastic neutron scattering (INS) to study spin excitations in superconducting NaFe0.985Co0.015As (C15) with static antiferromagnetic (AF) order along the a axis of the orthorhombic structure and ...
    • c-axis pressure-induced antiferromagnetic order in optimally P-doped BaFe2(As0.70P0.30)2 superconductor 

      Hu, Ding; Wang, Weiyi; Zhang, Wenliang; Wei, Yuan; Gong, Dongliang; Tam, David W.; Zhou, Panpan; Li, Yu; Tan, Guotai; Song, Yu; Georgii, Robert; Pedersen, Björn; Cao, Huibo; Tian, Wei; Roessli, Bertrand; Yin, Zhiping; Dai, Pengcheng (2018)
      Superconductivity in BaFe2(As1−xPx)2 iron pnictides emerges when its in-plane two-dimensional (2D) orthorhombic lattice distortion associated with nematic phase at Ts and three-dimensional (3D) collinear antiferromagnetic ...
    • Effect of Pnictogen Height on Spin Waves in Iron Pnictides 

      Zhang, Chenglin; Harriger, Leland W.; Yin, Zhiping; Lv, Weicheng; Wang, Miaoyin; Tan, Guotai; Song, Yu; Abernathy, D.L.; Tian, Wei; Egami, Takeshi; Haule, Kristjan; Kotliar, Gabriel; Dai, Pengcheng (2014)
      We use inelastic neutron scattering to study spin waves in the antiferromagnetic ordered phase of iron pnictide NaFeAs throughout the Brillouin zone. Comparing with the well-studied AFe2As2 (A=Ca, Sr, Ba) family, spin waves ...
    • Electron doping evolution of structural and antiferromagnetic phase transitions in NaFe1−xCoxAs iron pnictides 

      Tan, Guotai; Song, Yu; Zhang, Chenglin; Lin, Lifang; Xu, Zhuang; Hou, Tingting; Tian, Wei; Cao, Huibo; Li, Shiliang; Feng, Shiping; Dai, Pengcheng (2016)
      We use transport and neutron diffraction to study the electronic phase diagram of NaFe1−xCoxAs. In the undoped state, NaFeAs exhibits a tetragonal-to-orthorhombic structural transition below Tsfollowed by a collinear ...
    • Electron doping evolution of the magnetic excitations in NaFe1−xCoxAs 

      Carr, Scott V.; Zhang, Chenglin; Song, Yu; Tan, Guotai; Li, Yu; Abernathy, D.L.; Stone, M.B.; Granroth, G.E.; Perring, T.G.; Dai, Pengcheng (2016)
      We use time-of-flight (TOF) inelastic-neutron-scattering (INS) spectroscopy to investigate the doping dependence of magnetic excitations across the phase diagram of NaFe 1 − x Co x As with x = 0 , 0.0175, ...
    • Electron doping evolution of the neutron spin resonance in NaFe1−xCoxAs 

      Zhang, Chenglin; Lv, Weicheng; Tan, Guotai; Song, Yu; Carr, Scott V.; Chi, Songxue; Matsuda, M.; Christianson, A.D.; Fernandez-Baca, J.A.; Harriger, L.W.; Dai, Pengcheng (2016)
      Neutron spin resonance, a collective magnetic excitation coupled to superconductivity, is one of the most prominent features shared by a broad family of unconventional superconductors including copper oxides, iron pnictides, ...
    • Influence of doping on the spin dynamics and magnetoelectric effect in hexagonalᅠY0.7Lu0.3MnO3 

      Tian, W.; Tan, Guotai; Liu, Liu; Zhang, Jinxing; Winn, Barry; Hong, Tao; Fernandez-Baca, J.A.; Zhang, Chenglin; Dai, Pengcheng (2014)
      We use inelastic neutron scattering and dielectric constant measurements to study the doping influence on the spin dynamics and magnetoelectric (ME) effect in hexagonalY0.7Lu0.3MnO3. In undoped YMnO3 and LuMnO3, the Mn ...
    • Phase diagram and neutron spin resonance of superconducting NaFe1−xCuxAs 

      Tan, Guotai; Song, Yu; Zhang, Rui; Lin, Lifang; Xu, Zhuang; Tian, Long; Chi, Songxue; Graves-Brook, M.K.; Li, Shiliang; Dai, Pengcheng (2017)
      We use transport and neutron scattering to study the electronic phase diagram and spin excitations of NaFe1−xCuxAs single crystals. Similar to Co- and Ni-doped NaFeAs, a bulk superconducting phase appears near x≈2% with ...
    • Spin anisotropy due to spin-orbit coupling in optimally hole-doped Ba0:67K0:33Fe2As2 

      Song, Yu; Man, Haoran; Zhang, Rui; Lu, Xingye; Zhang, Chenglin; Wang, Meng; Tan, Guotai; Regnault, L.-P.; Su, Yixi; Kang, Jian; Fernandes, Rafael M.; Dai, Pengcheng (2016)
      We use polarized inelastic neutron scattering to study the temperature and energy dependence of spin space anisotropies in the optimally-hole-doped iron pnictide Ba0.67K0.33Fe2As2 (Tc=38 K). In the superconducting state, ...
    • Superconductivity and antiferromagnetism in Ba0.75K0.25Fe2As2 single crystals as seen by 57Fe Mossbauer spectroscopy 

      Munevar, J.; Micklitz, H.; Aguero, J.; Tan, Guotai; Zhang, Chenglin; Dai, Pengcheng; Baggio-Saitovitch, E. (2013)
    • Superconductivity and electronic fluctuations in Ba1−xKxFe2As2 studied by Raman scattering 

      Wu, S.-F.; Richard, P.; Ding, H.; Wen, H.-H.; Tan, Guotai; Wang, Meng; Zhang, Chenglin; Dai, Pengcheng; Blumberg, G. (2017)
      Using polarization-resolved electronic Raman scattering we study underdoped, optimally doped, and overdoped Ba1−xKxFe2As2 samples in the normal and superconducting states. We show that low-energy nematic fluctuations are ...
    • Temperature and polarization dependence of low-energy magnetic fluctuations in nearly optimally doped NaFe0.9785Co0.0215As 

      Song, Yu; Wang, Weiyi; Zhang, Chenglin; Gu, Yanhong; Lu, Xingye; Tan, Guotai; Su, Yixi; Bourdarot, Frédéric; Christianson, A.D.; Li, Shiliang; Dai, Pengcheng (2017)
      We use unpolarized and polarized neutron scattering to study the temperature and polarization dependence of low-energy magnetic fluctuations in nearly optimally doped NaFe0.9785Co0.0215As, with coexisting superconductivi ...