Evidence for a dynamical ground state in the frustrated pyrohafnate Tb2Hf2O7
| Autor: | L. Opherden, D. T. Adroja, J. Hornung, Adrian D. Hillier, V. K. Anand, Marc Uhlarz, Thomas Herrmannsdörfer, Pabitra Kumar Biswas, Jochen Wosnitza, Emmanuel Canévet, B. Lake, Jianhui Xu |
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| Rok vydání: | 2018 |
| Předmět: |
Neutron powder diffraction
Physics Condensed matter physics Relaxation (NMR) 02 engineering and technology Muon spin spectroscopy 021001 nanoscience & nanotechnology 01 natural sciences Heat capacity Magnetic susceptibility 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Ground state Spin-½ |
| Zdroj: | Physical Review B. 97 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | We report the physical properties of Tb2Hf2O7 based on ac magnetic susceptibility \chi_ac(T), dc magnetic susceptibility \chi(T), isothermal magnetization M(H), and heat capacity C_p(T) measurements combined with muon spin relaxation (\muSR) and neutron powder diffraction measurements. No evidence for long-range magnetic order is found down to 0.1 K. However, \chi_ac(T) data present a frequency-dependent broad peak (near 0.9 K at 16 Hz) indicating slow spin dynamics. The slow spin dynamics is further evidenced from the \muSR data (characterized by a stretched exponential behavior) which show persistent spin fluctuations down to 0.3 K. The neutron powder diffraction data collected at 0.1 K show a broad peak of magnetic origin (diffuse scattering) but no magnetic Bragg peaks. The analysis of the diffuse scattering data reveals a dominant antiferromagnetic interaction in agreement with the negative Weiss temperature. The absence of long-range magnetic order and the presence of slow spin dynamics and persistent spin fluctuations together reflect a dynamical ground state in Tb2Hf2O7. |
| Databáze: | OpenAIRE |
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