ISSN:
1572-9605
Keywords:
EPR
;
LSCD
;
isotope effect
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract The electron paramegnetic resonance (EPR) of Mn2+ doped into La2−x Sr x CuO4 was used to probe the copper spin relaxation via the bottleneck effect for oxygen isotope (16O and 18O)–substituted samples. It was found that the EPR linewidth is larger for the 18O isotope samples than for the 16O samples. For x = 0.03, the linewidth for the 18O sample is larger than for 16O sample by a factor of 2. The isotope effect is pronounced at low temperatures and decreases with increasing Sr concentration. This effect is quantitatively explained by the Cu2+ S = 1/2 spin relaxation to the lattice via Dzyaloshinski terms coupled linearly to the local Q 4/Q 5 tilting modes of the CuO6 octahedra as proposed by Kochelaev et al. [1] The Q 4/Q 5 modes are coupled sterically to the Q 2 Jahn–Teller modes considered to be relevant for the (bi)-polaron formation and thus for the high-temperature superconductivity (HTSC).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1026498123890
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