Magnetic Ordering in an Organic Polymer
Abstract
We describe preparation and magnetic properties of an organic π-conjugated polymer with very large magnetic moment and magnetic order at low temperatures. The polymer is designed with a large density of cross-links and alternating connectivity of radical modules with unequal spin quantum numbers (S), macrocyclic S = 2 and, cross-linking S = <FR SHAPE="SOL"><NU>1</NU><DE>2</DE></FR> modules, which permits large net S values for either ferromagnetic or antiferromagnetic exchange couplings between the modules. In the highly cross-linked polymer, an effective magnetic moment corresponding to an average S of about 5000 and slow reorientation of the magnetization by a small magnetic field (less than or equal to 1 oersted) below a temperature of about 10 kelvin are found. Qualitatively, this magnetic behavior is comparable to that of insulating spin glasses and blocked superparamagnets.
- Publication:
-
Science
- Pub Date:
- November 2001
- DOI:
- 10.1126/science.1065477
- Bibcode:
- 2001Sci...294.1503R
- Keywords:
-
- MAT SCI