Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Complete elastic moduli of La[sub 2[minus][ital x]]Sr[sub [ital x]]CuO[sub 4] ([ital x]=0. 00 and 0. 14) near the tetragonal-orthorhombic structural phase transition

Journal Article · · Physical Review, B: Condensed Matter; (United States)
; ;  [1];  [2]; ;  [3]; ;  [1]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States) Department of Physics, University of California, San Diego, La Jolla, California 92093 (United States)
  3. Institute for Inorganic Synthesis, Yamanashi University, Kofu 4000 (Japan)

We present resonant ultrasound spectroscopy measurements of the complete elastic moduli of La[sub 2[minus][ital x]]Sr[sub [ital x]]CuO[sub 4] ([ital x]=0.00 and 0.14). The [ital x] dependence of both the absolute values of the moduli in the tetragonal phase and the temperature dependences of the moduli near the structural phase transition is weak. In both materials [ital c][sub 44] and 1/2 ([ital c][sub 11][minus][ital c][sub 12]) are unaffected by the transition, [ital c][sub 33] shows a steplike drop broadened by fluctuations, and [ital c][sub 11] and [ital c][sub 66] decrease as 1/([ital T][minus][ital T][sub SPT]) for [ital T][gt][ital T][sub SPT] (where [ital T][sub SPT] is the structural phase transition temperature). We also present measurements of the anisotropic thermal expansion coefficients in La[sub 1.86]Sr[sub 0.14]CuO[sub 4] using a high-resolution capacitance dilatometer. These data when taken together raise serious questions about the standard interpretation of the structural phase transition in La[sub 2[minus][ital x]]Sr[sub [ital x]]CuO[sub 4].

OSTI ID:
6841823
Journal Information:
Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:18; ISSN PRBMDO; ISSN 0163-1829
Country of Publication:
United States
Language:
English