Speaker
Description
Single ion magnets (SIM's), are materials that show an energy barrier to spin reorientation without long range magnetic order. Such materials have been postulated to be useful as potential materials for high density data storage or to be used as Qubits. The origin of the effect lies in the crystal field splitting of the central lanthanoid ion. The determination of crystal field splitting has long been performed using INS and this has been readily extended to SIM's [1]. In recent years the operating temperature of these SIM's has increased dramatically with magnetic hysteresis observed above liquid nitrogen temperatures [2]. The limiting factor is no longer the height of the energy barrier for reorientation, but minimization of relaxation by varying methods such as quantum tunneling of magnetization and Orbach relaxation. Such phenomena have previously been shown to be measurable using INS and QENS techniques [3,4,5]. In our recent work we have revisited the INS of Na9[Ho(W5O18)2] to analyse both the presence or absence of a QENS signal to determine whether Orbach relaxation occurs [3]. We have also performed an analysis of the peak widths of the crystal field excitations and modelled these using a magnetoelastic model [4]. This reanalysis demonstrates that INS holds more information than just the energy scale of the system for single ion magnets.
[1] M. A. Dunstan et al, European Journal of Inorganic Chemistry 1089 (2019).
[2] F-S. Guo,et al, Science, 362, 1400 (2018)
[3] M. Roepke, et al, Physical Review B, 60, 9793 (1999)
[4] S.W. Lovesey, U. Staub, Physical Review B, 61, 9130 (2000)
[5] M. Ruminy, et. al, Physical Review B 95, 060414(R) (2017)
| Condition of submission | Yes |
|---|---|
| Pronouns | He/Him |
| Level of Expertise | Experienced Researcher |
| Which facility did you use for your research | Australian Centre for Neutron Scattering |
| Presenter Gender | Man |
