Raman modes of the apical oxygen in mercury-based superconductors

Journal Article · Fri Dec 01 00:00:00 EST 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.15078· OSTI ID:146767

Yang, I; Lee, H ^[1]; Hur, N H ^[2]; Yu, J ^[3]

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1. Department of Physics, Ewha Womans University, Seoul, 120-750 (Korea, Republic of)
2. Korea Research Institute of Standards and Science, Taejon, 305-606 (Korea, Republic of)
3. Department of Physics, Sogang University, Seoul, 121-742 (Korea, Republic of)

Recent studies suggest that the apical oxygen plays an important role in high-{ital T}{sub {ital c}} superconductivity of mercury-based superconductors HgBa{sub 2}Ca{sub {ital n}{minus}1}Cu{sub {ital n}}O{sub 2{ital n}+2+{delta}} [Hg-12({ital n}-1){ital n}]. Among strong Raman peaks at {similar_to}570 and {similar_to} 585 cm{sup {minus}1}, the mode at {similar_to} 585 cm{sup {minus}1} has been determined to be the {ital A}{sub 1{ital g}} mode of the apical oxygen. However, the origin of the mode near 570 cm{sup {minus}1} is still in question. In order to clarify the origin of the 570 cm{sup {minus}1} mode, we have carried out Raman measurements on the Hg{sub 1{minus}{ital x}}Tl{sub {ital x}}Ba{sub 2}(Ca{sub 0.86}Sr{sub 0.14}){sub 2}Cu{sub 3}O{sub 8+{delta}} systems, where the amount of the oxygen in the Hg/Tl-O plane is controlled by the doping level of Tl ions. The results show that the 570 cm{sup {minus}1} peak does not arise from the modes of the interstitial oxygens in the Hg/Tl-O plane, but from the {ital A}{sub 1{ital g}}-type mode of the apical oxygen. From our analysis, it is shown that the 570 cm{sup {minus}1} mode arises from the apical oxygen O{sub {ital A}} with the neighboring interstitial oxygen O{sub {delta}}, while the 585 cm{sup {minus}1} mode is from the O{sub {ital A}} without the nearest O{sub {delta}} neighbor. We conclude that the apical oxygens in the Hg-12({ital n}-1){ital n} systems can have two distinctive sets of O{sub {delta}} environment.

• OSTI ID: 146767
• Journal Information: Physical Review, B: Condensed Matter, Vol. 52, Issue 21; Other Information: PBD: 1 Dec 1995
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM OXIDES
CRYSTAL DOPING
RAMAN SPECTRA
CALCIUM OXIDES
CUPRATES
MERCURY OXIDES
STRONTIUM OXIDES
THALLIUM OXIDES
AMBIENT TEMPERATURE
CRYSTAL DEFECTS
HIGH-TC SUPERCONDUCTORS
INTERSTITIALS
PHONONS
STOICHIOMETRY
SUBSTOICHIOMETRY
TEMPERATURE DEPENDENCE
THALLIUM ADDITIONS
TRANSITION TEMPERATURE