Giant coercivity and high magnetic blocking temperatures for N23- radical-bridged dilanthanide complexes upon ligand dissociation

Selvan Demir; Miguel I Gonzalez; Lucy E Darago; William J Evans; Jeffrey R Long

doi:10.1038/s41467-017-01553-w

Giant coercivity and high magnetic blocking temperatures for N₂^3- radical-bridged dilanthanide complexes upon ligand dissociation

Nat Commun. 2017 Dec 15;8(1):2144. doi: 10.1038/s41467-017-01553-w.

Authors

Selvan Demir^{1

2}, Miguel I Gonzalez³, Lucy E Darago³, William J Evans⁴, Jeffrey R Long^{5

6

7}

Affiliations

¹ Department of Chemistry, University of California, Berkeley, CA, 94720, USA. selvan.demir@chemie.uni-goettingen.de.
² University of Goettingen, Institute of Inorganic Chemistry, Tammannstrasse 4, 37077, Goettingen, Germany. selvan.demir@chemie.uni-goettingen.de.
³ Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
⁴ Department of Chemistry, University of California, Irvine, CA, 92697, USA.
⁵ Department of Chemistry, University of California, Berkeley, CA, 94720, USA. jrlong@berkeley.edu.
⁶ Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA. jrlong@berkeley.edu.
⁷ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. jrlong@berkeley.edu.

Abstract

Increasing the operating temperatures of single-molecule magnets-molecules that can retain magnetic polarization in the absence of an applied field-has potential implications toward information storage and computing, and may also inform the development of new bulk magnets. Progress toward these goals relies upon the development of synthetic chemistry enabling enhancement of the thermal barrier to reversal of the magnetic moment, while suppressing alternative relaxation processes. Herein, we show that pairing the axial magnetic anisotropy enforced by tetramethylcyclopentadienyl (Cp^Me4H) capping ligands with strong magnetic exchange coupling provided by an N₂^3- radical bridging ligand results in a series of dilanthanide complexes exhibiting exceptionally large magnetic hysteresis loops that persist to high temperatures. Significantly, reducing the coordination number of the metal centers appears to increase axial magnetic anisotropy, giving rise to larger magnetic relaxation barriers and 100-s magnetic blocking temperatures of up to 20 K, as observed for the complex [K(crypt-222)][(Cp^Me4H₂Tb)₂(μ-[Formula: see text])].

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Algorithms
Anisotropy
Crystallography, X-Ray
Free Radicals / chemistry*
Hot Temperature*
Lanthanoid Series Elements / chemistry*
Ligands
Magnetic Phenomena*
Models, Molecular
Molecular Structure
Organometallic Compounds / chemistry*
Thermodynamics

Substances

Free Radicals
Lanthanoid Series Elements
Ligands
Organometallic Compounds

Grants and funding

S10 RR027172/RR/NCRR NIH HHS/United States