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Title: Temperature Dependent Bilayer Ferromagnetism in Sr 3Ru 2O 7

Abstract

The ruthenium-based perovskites exhibit a wide variety of interesting collective phenomena related to magnetism originating from the Ru 4d electrons. Much remains unknown concerning the nature of magnetic fluctuations and excitations in these systems. We present results of detailed inelastic neutron scattering measurements of Sr{sub 3}Ru{sub 2}O{sub 7} as a function of temperature, probing the ferromagnetic fluctuations of the bilayer structure. A magnetic response is clearly visible for a range of temperatures, T=3.8 K up to T=100 K, and for energy transfers between {h_bar}{omega}=2 and 14 meV. These measurements indicate that the ferromagnetic fluctuations manifest in the bilayer structure factor persist to surprisingly large temperatures. This behavior may be related to the proximity of the system in zero magnetic field to the metamagnetic/ferromagnetic transition.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [2]
  1. ORNL
  2. National Institute of Standards and Technology (NIST)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Flux Isotope Reactor
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1003325
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 73; Journal Issue: 17
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRONS; ENERGY TRANSFER; FERROMAGNETISM; FLUCTUATIONS; MAGNETIC FIELDS; MAGNETISM; NEUTRON DIFFRACTION; PEROVSKITES; INELASTIC SCATTERING; STRUCTURE FACTORS

Citation Formats

Stone, Matthew B, Lumsden, Mark D, Jin, Rongying, Sales, Brian C, Mandrus, David, Nagler, Stephen E, and Qiu, Y. Temperature Dependent Bilayer Ferromagnetism in Sr3Ru2O7. United States: N. p., 2006. Web. doi:10.1103/PhysRevB.73.174426.
Stone, Matthew B, Lumsden, Mark D, Jin, Rongying, Sales, Brian C, Mandrus, David, Nagler, Stephen E, & Qiu, Y. Temperature Dependent Bilayer Ferromagnetism in Sr3Ru2O7. United States. doi:10.1103/PhysRevB.73.174426.
Stone, Matthew B, Lumsden, Mark D, Jin, Rongying, Sales, Brian C, Mandrus, David, Nagler, Stephen E, and Qiu, Y. Sun . "Temperature Dependent Bilayer Ferromagnetism in Sr3Ru2O7". United States. doi:10.1103/PhysRevB.73.174426.
@article{osti_1003325,
title = {Temperature Dependent Bilayer Ferromagnetism in Sr3Ru2O7},
author = {Stone, Matthew B and Lumsden, Mark D and Jin, Rongying and Sales, Brian C and Mandrus, David and Nagler, Stephen E and Qiu, Y.},
abstractNote = {The ruthenium-based perovskites exhibit a wide variety of interesting collective phenomena related to magnetism originating from the Ru 4d electrons. Much remains unknown concerning the nature of magnetic fluctuations and excitations in these systems. We present results of detailed inelastic neutron scattering measurements of Sr{sub 3}Ru{sub 2}O{sub 7} as a function of temperature, probing the ferromagnetic fluctuations of the bilayer structure. A magnetic response is clearly visible for a range of temperatures, T=3.8 K up to T=100 K, and for energy transfers between {h_bar}{omega}=2 and 14 meV. These measurements indicate that the ferromagnetic fluctuations manifest in the bilayer structure factor persist to surprisingly large temperatures. This behavior may be related to the proximity of the system in zero magnetic field to the metamagnetic/ferromagnetic transition.},
doi = {10.1103/PhysRevB.73.174426},
journal = {Physical Review B},
number = 17,
volume = 73,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • Sr{sub 3}Ru{sub 2}O{sub 7} is a layered compound and a member of the Ruddlesden-Popper-type compound series of Sr{sub n+1}Ru{sub n}O{sub 3n+1} (n=1, 2, and n={infinity}) with n=2. Single crystals of Sr{sub 3}Ru{sub 2}O{sub 7} were grown and characterized, providing an unambiguous indication of a rich ferromagnetic state with T{sub c}=104 K and a saturated moment of 1.30{plus_minus}0.05{mu}{sub B}/Ru at T=5 K. Among many interesting features, a magnetic spin reorientation transition is observed, suggesting that moments in the ordered state order ferromagnetically with a slight canting on adjacent spins. Negative magnetoresistance, commonly occurring in ferromagnets, is relatively large (19{percent} at 10more » T and T=30 K), suggesting a significant suppression of spin-flip scattering by the applied magnetic field. The results are discussed with comparisons drawn with sister compounds Sr{sub 2}RuO{sub 4}, SrRuO{sub 3} and other related systems.« less
  • IR and Raman spectra of Ca{sub 2}MgSi{sub 2}O{sub 7}, Ca{sub 2}ZnSi{sub 2}O{sub 7} and Sr{sub 2}MgSi{sub 2}O{sub 7} oriented single crystals and powders have been measured. The temperature dependence of phonons has been established in the 4-650 K range. Discussion of the results has been performed on the basis of factor group approach for the tetragonal P4-bar 2{sub 1}m (D{sub 2d}{sup 3}) space group with Z=2. The assignment of the bands observed to the internal and external modes has been made on their polarization behaviour, phonon energy calculations and literature data. The evidences of the LO-TO splitting and commensurate (C)more » to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. As a representative example, the results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of Ca{sub 2}ZnSi{sub 2}O{sub 7}. - Graphical abstract: Raman and IR spectra of Ca{sub 2}MgSi{sub 2}O{sub 7}, Ca{sub 2}ZnSi{sub 2}O{sub 7}, Sr{sub 2}MgSi{sub 2}O{sub 7} have been measured. The temperature dependence of phonons has been established in the 4-650 K range. The evidences of the LO-TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. Highlights: Black-Right-Pointing-Pointer Polarized IR and Raman spectra of pyrosilicates single crystals have been studied. Black-Right-Pointing-Pointer Temperature dependence of the phonon bands and LO-TO splitting have been analysed. Black-Right-Pointing-Pointer Commensurate to incommensurate and to normal phase have been evidenced in the spectra. Black-Right-Pointing-Pointer Phonon calculations have been used in assignment of the normal modes. Black-Right-Pointing-Pointer Stimulated Raman spectra of Ca{sub 2}ZnSi{sub 2}O{sub 7} crystal have been measured and analysed.« less
  • Cited by 2
  • The crystal structure of the ruthenate Sr{sub 3}Ru{sub 2}O{sub 7} as a function of temperature (5--305 K) and pressure (ambient -0.62 GPa) was studied by neutron diffraction. Upon cooling, the lattice parameter c and the rotation angle of the oxygen octahedra {phi} increase for 305K>T>50K, and decrease for 20K>T>5K. As pressure is applied at room temperature, the outer apical Ru-O bond expands. This remarkable behavior is discussed in terms of modification of the occupation of energy levels of the Ru{sup 4+} ion in the crystalline electric field of the oxygen octahedron and a crossover to Fermi-liquid behavior at low temperature.more » The very anisotropic thermal expansion leads, in sintered powder samples, to a high degree of strain, which is relieved somewhat with each cooling cycle.« less
  • Cited by 4