Structural, magnetic and phonon properties of Cr(III)-doped perovskite metal formate framework [(CH{sub 3}){sub 2}NH{sub 2}][Mn(HCOO){sub 3}]

Journal Article · Sun May 15 00:00:00 EDT 2016 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2016.02.010· OSTI ID:22584066

Mączka, Mirosław ^[1]; Gągor, Anna; Hermanowicz, Krzysztof ^[1]; Sieradzki, Adam ^[2]; Macalik, Lucyna; Pikul, Adam ^[1]

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1. Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Box 1410, 50-950 Wrocław 2 (Poland)
2. Department of Experimental Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław (Poland)

We have incorporated Cr(III) into [(CH{sub 3}){sub 2}NH{sub 2}][Mn(HCOO){sub 3}] (DMMn) multiferroic metal organic framework (MOF). The highest concentration of Cr(III) in the synthesized samples reached 15.9 mol%. The obtained samples were characterized by powder and single-crystal X-ray diffraction, DSC, magnetic susceptibility, dielectric, EPR, Raman and IR methods. These methods and the performed chemical analysis revealed that electrical charge neutrality after substitution of Cr(III) for Mn(II) is maintained by partial replacement of dimethylammonium (DMA{sup +}) cations by neutral HCOOH molecules. These changes in the chemical composition are responsible for weakening of the hydrogen bonds and decreased flexibility of the framework. This in turn leads to lowering of the ferroelectric phase transition temperature, observed around 185 K for undoped DMMn and around 155 K for the sample containing 3.1 mol% of Cr(III), and lack of macroscopic phase transition for the samples with Cr(III) content of 8.2 and 15.9 mol %. Another interesting effect observed for the studied samples is pronounced strengthening of the weak ferromagnetism of in Cr(III)-doped samples, associated with slight decrease of the ferromagnetic ordering temperature from 8.5 K for DMMn to 7.0 K for the sample with 15.9 mol % Cr(III) content. - Graphical abstract: Incorporation of Cr(III) into [(CH3)2NH2[Mn(HCOO)3] framework increases the magnetization. - Highlights: • Chromium(III) substitutes for Mn(II) in the studied MOF. • Charge neutrality is maintained by replacing DMA{sup +} cations by neutral HCOOH molecules. • Compounds with 8.2 and 15.9% of Cr(III) show no phase transition above 100 K. • Doping with Cr(III) increases magnetization.

• OSTI ID: 22584066
• Journal Information: Journal of Solid State Chemistry, Vol. 237; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CATIONS
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHROMIUM
DOPED MATERIALS
ELECTRON SPIN RESONANCE
FERROELECTRIC MATERIALS
FERROMAGNETISM
FORMATES
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MONOCRYSTALS
ORGANOMETALLIC COMPOUNDS
PEROVSKITE
PHASE TRANSFORMATIONS
PHONONS
TRANSITION TEMPERATURE
X RADIATION
X-RAY DIFFRACTION