New Article – Frustrated Magnet Mn3Al2Ge3O12 Garnet: Crystal Growth by the Optical Floating Zone Method
28th Feb, 2023
Frustrated magnetism is an interesting phenomenon often found in electrically insulating materials. In order to study materials that exhibit frustrated magnetism it is often necessary to produce a relatively large, single crystal with high purity.
In a new study, published in the journal Crystals, a team of researchers from the UK and Switzerland have, for the first time, shown the growth of a large, high-quality single crystal of the Mn3Al2Ge3O12 garnet by the floating zone (FZ) method. The Photonic Science Laue X-ray diffraction system was used to check the purity of the crystal during the development of this method.
Manisha Islam 1,* , Monica Ciomaga Hatnean 1,2,3 , Geetha Balakrishnan 1 and Oleg A. Petrenko 1
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute (PSI), 5232 Villigen, Switzerland
- Materials Discovery Laboratory, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
Abstract Frustrated Magnet Mn3Al2Ge3O12 Garnet: Crystal Growth by the Optical Floating Zone Method
Mn3Al2Ge3O12 is a member of the garnet family of compounds, A3B2(CO4)3, whose magnetic properties are affected by a high degree of geometrical frustration. The magnetic frustration is at the origin of the intriguing magnetic properties that these materials exhibit, such as a long range hidden order derived from multipoles formed from 10-spin loops in the gadolinium gallium garnet, Gd3Ga5O12. Mn3Al2Ge3O12 garnet is isostructural to the thoroughly investigated Gd garnets, Gd3Ga5O12 and Gd3Al5O12. Moreover, in Mn3Al2Ge3O12, the Heisenberg-like Mn2+ magnetic ions (L = 0) are also arranged in corner sharing triangles that form a hyperkagomé structure.
The identical crystallographic structures and similar Heisenberg-like behaviour of the magnetic ions make manganese aluminium germanium garnet the closest compound to the gadolinium garnets in its magnetic properties. Here, we report, for the first time, the growth of a large, high quality single crystal of the Mn3Al2Ge3O12 garnet by the floating zone method. X-ray diffraction techniques were used to characterise and confirm the high crystalline quality of the Mn3Al2Ge3O12 crystal boule. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering of the Mn2+ ions below TN = 6.5 K. The high quality of the single crystal obtained makes it ideal for detailed investigations of the magnetic properties of the system, especially using neutron scattering techniques.
Citation: Islam, M.; Ciomaga Hatnean, M.; Balakrishnan, G.; Petrenko, O.A. Frustrated Magnet Mn3Al2Ge3O12 Garnet: Crystal Growth by the Optical Floating Zone Method. Crystals 2023, 13, 397. https://doi.org/10.3390/cryst13030397
Academic Editor: Ludmila Isaenko
Received: 27 January 2023
Revised: 17 February 2023
Accepted: 23 February 2023
Published: 25 February 2023
Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
Manisha Islam and the Department of Physics, at the University of Warwick, report for the first time, the growth of a large, high-quality single crystal of the Mn3Al2Ge3O12 garnet by the floating zone method. X-ray diffraction techniques were used to characterise and confirm the high crystalline quality of the Mn3Al2Ge3O12 crystal.
A backscattering X-ray Photonic-Science Laue camera system was to investigate the quality of the Frustrated Magnet Mn3Al2Ge3O12 . A 3 cm long single crystal was isolated from the crystal boule showing the best crystalline quality.
The crystal quality of the boules was investigated using a backscattering X-ray Photonic-Science Laue camera system.
As-grown crystal boule of Mn3Al2Ge3O12 (sample labeled MAGG_C2), prepared by the floating zone technique, in nitrogen gas atmosphere, at a pressure of 1 bar, using a growth rate of 20 mm h−1 (top). A single crystal of ∼3 cm length was isolated from the Mn3Al2Ge3O12crystal boule, labeled as region A. Also shown are the X-ray Laue back reflection photographs showing the  and  orientations of an aligned sample used for magnetic properties measurements (bottom).