ISIS Neutron and Muon Source Data Journal
This is a page describing data taken during an experiment at the ISIS Neutron and Muon Source. Information about the ISIS Neutron and Muon Source can be found at https://www.isis.stfc.ac.uk.
Inelastic Neutron Scattering study to explore Gapless Excitations in a New S = 5/2 Sawtooth Spin Chain with Strong Geometric Frustration
Abstract: CaFe2O(PO4)2 (CFPO) is a rare example of a well-isolated S = 5/2 sawtooth spin chain built from corner-sharing Fe3+ triangles, combining strong geometric frustration and one-dimensionality. Magnetic susceptibility yields Curie Temperature = 1073 K and a large frustration parameter f = 70. Heat capacity and NMR study reveal three successive low-temperature magnetic transitions (15.5, 10.4, and 7.8 K), a broad Knight shift maximum, persistent spin dynamics, and strong short-range correlations. Despite a coupling ratio Jbb/Jvb=0.61 which predicts a singlet ground state for S = 1/2 analogs, CFPO exhibits gapless excitations. Interestingly CFPO also shows evidence of Magneto-Dielectric(MD) coupling.Inelastic neutron scattering (INS) on such spin chain system at MARI will allow direct mapping of the spin excitation spectrum over a wide Q E range, enabling extraction of exchange constants, identification of dispersion features, and detection of possible excitation continua from frustration. INS can also reveal MD coupling through linewidths, energy shifts, and Q-dependent intensity variations, clarifying how geometric frustration and S = 5/2 spin size conspire to produce the extended cooperative paramagnetic regime observed in CFPO.
Principal Investigator: Dr Tathamay Basu
Experimenter: Dr Devashi Adroja
Experimenter: Mr Gourab Roy
Experimenter: Mr Mohit Kumar Kumar
Experimenter: Mr Sayan Ghosh
Experimenter: Miss Ekta Kushwaha
DOI: 10.5286/ISIS.E.RB2590217
ISIS Experiment Number: RB2590217
| Part DOI | Instrument | Public release date | Download Link |
|---|---|---|---|
| 10.5286/ISIS.E.RB2590217-1 | MARI | 09 October 2028 | Download |
Publisher: STFC ISIS Neutron and Muon Source
Data format: RAW/Nexus
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Data Citation
The recommended format for citing this dataset in a research
publication is as:
[author], [date], [title], [publisher],
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For Example:
Dr Tathamay Basu et al; (2025): Inelastic Neutron Scattering study to explore Gapless Excitations in a New S = 5/2 Sawtooth Spin Chain with Strong Geometric Frustration, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB2590217
Data is released under the CC-BY-4.0 license.
