Pressure-induced enhancement of the ferromagnetic intermolecular interaction of an. alpha. -nitronyl nitroxide organic radical

Journal Article · · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00011a014· OSTI ID:5410130

Awaga, Kunio; Maruyama, Yusei ^[1]

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1. Institute for Molecular Science, Okazaki (Japan)

The effect of high pressure on the ferromagnetic properties of a crystalline sample of an organic radical, 2-(4-nitrophenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxy 3-oxide (I), has been studied with the use of a combination of a Faraday susceptometer and a Be-Cu high-pressure clamp cell. The magnetic susceptibility of I increases markedly with increasing pressure at low temperatures, and furthermore its increment increases monotonically with decreasing temperature down to about 5 K. The Weiss constant under a pressure of 9 kbar corresponds to a 40% increase in the ferromagnetic intermolecular interaction, and the magnetization at 9 kbar also comes to saturation more rapidly compared with the behavior under an ambient pressure. A simple calculation of the intermolecular overlap integrals between the frontier orbitals can semiquantitatively interpret the pressure-induced enhancement of the ferromagnetic coupling.

• OSTI ID: 5410130
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 2:5; ISSN CMATE; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
DATA
EXPERIMENTAL DATA
FERROMAGNETISM
INFORMATION
MAGNETIC PROPERTIES
MAGNETISM
MEASURING METHODS
NITROXYL RADICALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
PRESSURE EFFECTS
RADICALS