Browsing by Author "Yang, W. L."

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Ferromagnetic Enhancement of CE-Type Spin Ordering in (Pr, Ca)MnO(3)
(2011-05-04)
Zhou, S. Y.
;
Zhu, Y.
;
Langner, M. C.
;
Chuang, Y. -D.
;
Yu, P.
We present resonant soft x-ray scattering results from small bandwidth manganites (Pr, Ca)MnO(3), which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperature and enhanced by ferromagnetism in the macroscopically insulating state (FM-I). Our results reveal the fragility of the CE-type ordering that underpins the colossal magnetoresistance effect in this system, as well as an unexpected cooperative interplay between FM-I and CE-type SO which is in contrast to the competitive interplay between the ferromagnetic metallic state and CE-type ordering.
Ferromagnetic Enhancement of CE-Type Spin Ordering in (Pr, Ca)MnO3
(2011-05-04)
Zhou, S. Y.
;
Zhu, Y.
;
Langner, M. C.
;
Chuang, Y. -D.
;
Yu, P.
We present resonant soft x-ray scattering results from small bandwidth manganites (Pr, Ca)MnO3, which show that the CE-type spin ordering (SO) at the phase boundary is stabilized only below the canted antiferromagnetic transition temperature and enhanced by ferromagnetism in the macroscopically insulating state (FM-I). Our results reveal the fragility of the CE-type ordering that underpins the colossal magnetoresistance effect in this system, as well as an unexpected cooperative interplay between FM-I and CE-type SO which is in contrast to the competitive interplay between the ferromagnetic metallic state and CE-type ordering.
Observation of a three-dimensional quasi-long-range electronic supermodulation in YBa2Cu3O7 (-) (x)/La0.7Ca0.3MnO3 heterostructures
(2016-03-01)
He, Junfeng
;
Shafer, Padraic
;
Mion, Thomas R.
;
Vu Thanh Tra
;
He, Qing
Recent developments in high-temperature superconductivity highlight a generic tendency of the cuprates to develop competing electronic (charge) supermodulations. While coupled with the lattice and showing different characteristics in different materials, these supermodulations themselves are generally conceived to be quasi-two-dimensional, residing mainly in individual CuO2 planes, and poorly correlated along the c axis. Here we observed with resonant elastic X-ray scattering a distinct type of electronic supermodulation in YBa2Cu3O7 (- x) (YBCO) thin films grown epitaxially on La0.7Ca0.3MnO3 (LCMO). This supermodulation has a periodicity nearly commensurate with four lattice constants in-plane, eight out of plane, with long correlation lengths in three dimensions. It sets in far above the superconducting transition temperature and competes with superconductivity below this temperature for electronic states predominantly in the CuO2 plane. Our finding sheds light on the nature of charge ordering in cuprates as well as a reported long-range proximity effect between superconductivity and ferromagnetism in YBCO/LCMO heterostructures.
Prominent role of oxygen in the multiferroicity of DyMnO3 and TbMnO3: A resonant soft x-ray scattering spectroscopy study
(2016-07-21)
Huang, S. W.
;
Lee, J. M.
;
Jeng, Horng-Tay
;
Shao, YuCheng
;
Wray, L. Andrew
Oxygen is known to play an important role in the multiferroicity of rare earth manganites; however, how this role changes with rare earth elements is still not fully understood. To address this question, we have used resonant soft x-ray scattering spectroscopy to study the F-type (0, tau, 0) diffraction peak from the antiferromagnetic order in DyMnO3 and TbMnO3. We focus on the measurements at O K edge of these two manganites, supplemented by the results at Mn L-2 and Dy M-5 edge of DyMnO3. We show that the electronic states of different elements are coupled more strongly in DyMnO3 than in TbMnO3, presumably due to the stronger lattice distortion and the tendency to develop E-type antiferromagnetism in the ferroelectric state that promote the orbital hybridization. We also show that the anomaly in the correlation length of (0, tau, 0) peak in DyMnO3 signifies the exchange interaction between Mn and rare earth spins. Our findings reveal the prominent role of oxygen orbitals in the multiferroicity of rare earth manganites and the distinct energetics between them.