|
1
|
Figueiras FG, Karpinsky D, Tavares PB, Gonçalves JN, Yañez-Vilar S, Moreira Dos Santos AF, Franz A, Tovar M, Agostinho Moreira J, Amaral VS. Novel multiferroic state and ME enhancement by breaking the AFM frustration in LuMn 1-xO 3. Phys Chem Chem Phys 2017; 19:1335-1341. [PMID: 27973632 DOI: 10.1039/c6cp07682c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study provides a comprehensive insight into the effects of controlled off-stoichiometry on the structural and multiferroic properties of the hexagonal manganite LuMn1-xO3+δ (x = 0.02; δ ∼ 0), supported by neutron powder diffraction measurements confirming single phase P63cm symmetry and evidencing a relevant ferromagnetic component, below TN ∼ 90 K, which breaks the archetypal geometrically frustrated antiferromagnetic state typically ascribed to LuMnO3. The perturbations in the triangular disposition of spins prompt an additional electric polarization contribution and a clear enhancement of the magnetoelectric coupling which are in good agreement with the results of first principles calculations. In addition, Raman spectroscopy, dielectric permittivity, pyroelectric current and magnetic measurements as a function of temperature point out the precursor effects of the magnetic phase transitions involving a strong coupling between spins, lattice and electric order, even above the Néel temperature.
Collapse
Affiliation(s)
- F G Figueiras
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal. and IFIMUP and IN, Institute of Nanoscience and Nanotechnology, Dep de Física e Astronomia da Universidade do Porto, 4169-007 Porto, Portugal
| | - D Karpinsky
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal. and National Research University of Electronic Technology "MIET", Zelenograd, Moscow, Russia and Scientific and Practical Materials Research Centre, National Academy of Sciences of Belarus, Minsk, Belarus
| | - P B Tavares
- Centro de Química-Vila Real, Departamento de Química, ECVA, Universidade de Trás-os-Montes & Alto-Douro, 5001-801 Vila Real, Portugal
| | - J N Gonçalves
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal.
| | - S Yañez-Vilar
- IFIMUP and IN, Institute of Nanoscience and Nanotechnology, Dep de Física e Astronomia da Universidade do Porto, 4169-007 Porto, Portugal
| | - A F Moreira Dos Santos
- Quantum Condensed Matter Div., Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831, USA
| | - A Franz
- Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - M Tovar
- Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - J Agostinho Moreira
- IFIMUP and IN, Institute of Nanoscience and Nanotechnology, Dep de Física e Astronomia da Universidade do Porto, 4169-007 Porto, Portugal
| | - V S Amaral
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal.
| |
Collapse
|
|
2
|
Figueiras FG, Karpinsky D, Tavares PB, Das S, Leitão JV, Brück EH, Moreira JA, Amaral VS. Breaking the geometric magnetic frustration in controlled off-stoichiometric LuMn1+zO3+δ compounds. Phys Chem Chem Phys 2016; 18:13519-23. [PMID: 27140064 DOI: 10.1039/c6cp01562j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study explores controlled off-stoichiometric LuMn1+zO3+δ (|z| < 0.1) compounds, intended to retain the utter LuMnO3 intrinsic hexagonal symmetry and ferroelectric properties. X-ray powder diffraction measurements evidenced a single phase P63cm structure. Thermo-gravimetric experiments show a narrow impact of oxygen vacancies while a distinguishable gas exchange at ∼700 K, a surprisingly lower temperature when compared to perovskite systems. A comparison of different nominal ceramics revealed pertinent structural and magnetic property variations owing to subtle self-doping effects. Deviations from the archetypal antiferromagnetic state were detected below ∼90 K suggesting local rearrangements of the nominal Mn(3+) ions matrix, breaking the ideal geometrical spin frustration, leading to a non-compensated magnetic structure.
Collapse
Affiliation(s)
- F G Figueiras
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal. and IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Physics and Astronomy Department, Faculty of Sciences of University of Porto, 4169-007 Porto, Portugal
| | - D Karpinsky
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal.
| | - P B Tavares
- Centro de Química, Trás-os-Montes & Alto-Douro University, 5001-801 Vila Real, Portugal
| | - Soma Das
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal.
| | - J V Leitão
- FAME, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands
| | - E H Brück
- FAME, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands
| | - J Agostinho Moreira
- IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Physics and Astronomy Department, Faculty of Sciences of University of Porto, 4169-007 Porto, Portugal
| | - V S Amaral
- Physics Department & CICECO-AIM, Aveiro University, 3810-193 Aveiro, Portugal.
| |
Collapse
|