# Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)(3)(boaDTDA)](n) (Ln = Sm, La) using implanted muons.

## Abstract

We present the results of muon-spin relaxation (mu+SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF2(pyz) we identify a transition to long range magnetic order taking place at T-N = 0.6(1) K, allowing us to estimate a ratio with the intrachain exchange of T-N/vertical bar J vertical bar approximate to 0.1 and the ratio of interchain to intrachain exchange coupling as vertical bar J'/J vertical bar approximate to 0.05. The ferromagnetic chain [Sm(hfac)(3)(boaDTDA)](n) undergoes an ordering transition at T-c = 2.8(1) K, seen via a broad freezing of dynamic fluctuations on the muon (microsecond) timescale and implying T-c/vertical bar J vertical bar approximate to 0.6. The ordered radical moment continues to fluctuate on this timescale down to 0.3 K, while the Sm moments remain disordered. In contrast, the radical spins in [La(hfac)(3)(boaDTDA)](n) remain magnetically disordered down to T = 0.1 K suggesting T-c/vertical bar J vertical bar < 0.17.

- Authors:

- Publication Date:

- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States)

- Sponsoring Org.:
- Engineering and Physical Sciences Research Council (EPSRC); Natural Science and Engineering Research Council of Canada

- OSTI Identifier:
- 1548288

- DOE Contract Number:
- AC02-06CH11357

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Physics. Condensed Matter

- Additional Journal Information:
- Journal Volume: 31; Journal Issue: 39

- Country of Publication:
- United States

- Language:
- English

- Subject:
- muon-spin relaxation; one-dimensional magnetism; radical magnetism

### Citation Formats

```
Lancaster, T., Huddart, B. M., Williams, R. C., Xiao, F., Franke, K. J. A., Baker, P. J., Pratt, F. L., Blundell, S. J., Schlueter, J. A., Mills, M. B., Maahs, A. C., and Preuss, K. E.
```*Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)(3)(boaDTDA)](n) (Ln = Sm, La) using implanted muons.*. United States: N. p., 2019.
Web. doi:10.1088/1361-648X/ab2cb6.

```
Lancaster, T., Huddart, B. M., Williams, R. C., Xiao, F., Franke, K. J. A., Baker, P. J., Pratt, F. L., Blundell, S. J., Schlueter, J. A., Mills, M. B., Maahs, A. C., & Preuss, K. E.
```*Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)(3)(boaDTDA)](n) (Ln = Sm, La) using implanted muons.*. United States. doi:10.1088/1361-648X/ab2cb6.

```
Lancaster, T., Huddart, B. M., Williams, R. C., Xiao, F., Franke, K. J. A., Baker, P. J., Pratt, F. L., Blundell, S. J., Schlueter, J. A., Mills, M. B., Maahs, A. C., and Preuss, K. E. Wed .
"Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)(3)(boaDTDA)](n) (Ln = Sm, La) using implanted muons.". United States. doi:10.1088/1361-648X/ab2cb6.
```

```
@article{osti_1548288,
```

title = {Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)(3)(boaDTDA)](n) (Ln = Sm, La) using implanted muons.},

author = {Lancaster, T. and Huddart, B. M. and Williams, R. C. and Xiao, F. and Franke, K. J. A. and Baker, P. J. and Pratt, F. L. and Blundell, S. J. and Schlueter, J. A. and Mills, M. B. and Maahs, A. C. and Preuss, K. E.},

abstractNote = {We present the results of muon-spin relaxation (mu+SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF2(pyz) we identify a transition to long range magnetic order taking place at T-N = 0.6(1) K, allowing us to estimate a ratio with the intrachain exchange of T-N/vertical bar J vertical bar approximate to 0.1 and the ratio of interchain to intrachain exchange coupling as vertical bar J'/J vertical bar approximate to 0.05. The ferromagnetic chain [Sm(hfac)(3)(boaDTDA)](n) undergoes an ordering transition at T-c = 2.8(1) K, seen via a broad freezing of dynamic fluctuations on the muon (microsecond) timescale and implying T-c/vertical bar J vertical bar approximate to 0.6. The ordered radical moment continues to fluctuate on this timescale down to 0.3 K, while the Sm moments remain disordered. In contrast, the radical spins in [La(hfac)(3)(boaDTDA)](n) remain magnetically disordered down to T = 0.1 K suggesting T-c/vertical bar J vertical bar < 0.17.},

doi = {10.1088/1361-648X/ab2cb6},

journal = {Journal of Physics. Condensed Matter},

number = 39,

volume = 31,

place = {United States},

year = {2019},

month = {10}

}