Dynamic lattice distortions in Sr2RuO4: microscopic studies by perturbed angular correlation spectroscopy and ab initio calculations

• Published in: Journal of physics. Condensed matter Vol. 22; no. 38; p. 385602
• Main Authors: Mishra, S N, Rots, M, Cottenier, S
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 29.09.2010; Institute of Physics
• Subjects: Angular correlation; Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Distortion; Dynamics; Exact sciences and technology; Fluctuation; Lattices; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mathematical analysis; Mössbauer effect; other γ-ray spectroscopy; Physics; Quadrupole interaction; Electric field gradients; Perturbed angular correlation; Ruthenates; Structure stability; Temperature effects; Quadrupole interactions; Strontium compounds; Spin fluctuations; Instability; Local spin density approximation; Ab initio calculations
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/22/38/385602

Applying time differential perturbed angular correlation (TDPAC) spectroscopy and ab initio calculations, we have investigated possible lattice instabilities in Sr(2)RuO(4) by studying the electric quadrupole interaction of a (111)Cd probe at the Ru site. We find evidence for a dynamic lattice distortion, revealed from the observations of: (i) a rapidly fluctuating electric-field gradient (EFG) tensor showing non-Arrhenius relaxation, (ii) an anomalous temperature dependence of the quadrupole interaction frequency, and (iii) a monotonic increase of the EFG asymmetry (η) below 300 K. We argue that the observed dynamic lattice distortion is caused by strong spin fluctuations associated with the inherent magnetic instability in Sr(2)RuO(4).