Electronic structure and magnetic anisotropy for nickel-based molecular magnets

Abstract

Recent magnetic measurements on tetra-nickel molecular magnets [Ni(hmp)(ROH)Cl]${}_4$, where R=CH${}_3$, CH${}_2$CH${}_3$, or (CH${}_2$)${}_2$C(CH${}_3$)${}_3$ and hmp${}^{-}$ is the monoanion of 2-hydroxymethylpyridine, revealed a strong exchange bias prior to the external magnetic field reversal as well as anomalies in electron paramagnetic resonance peaks at low temperatures. To understand the exchange bias and observed anomalies, we calculate the electronic structure and magnetic properties for the Ni${}_4$ molecules with the three different ligands, employing density-functional theory. Considering the optimized structure with possible collinear spin configurations, we determine a total spin of the lowest-energy state to be S=0, which does not agree with experiment. We also calculate magnetic anisotropy barriers for all three types of Ni${}_4$ molecules to be in the range of 4-6 K.

Will be presented at MMM conference 2004

References in corpus (4)

• DFT calculation of the intermolecular exchange interaction in the magnetic Mn${}_4$ dimer
• Properties of low-lying excited manifolds in the Mn12 acetate
• Electronic structure and magnetic anisotropy of the [Co_4(hmp)_4(CH_3OH)_4Cl_4] molecule
• Electronic, magnetic, and vibrational properties of the molecular magnet Mn4 monomer and dimer

Cited by in corpus (3)

• Fermi Orbital Derivatives in Self-Interaction Corrected Density Functional Theory: Applications to Closed Shell Atoms
• Strongly Correlated Electrons in the $[Ni(hmp)(ROH)X{]}_4$ Single Molecule Magnet: A DFT+U Study
• Observation of field-dependent magnetic parameters in the magnetic molecule {Ni4Mo12}