Sumit Bhaduri

Spin-parity dependent tunneling of magnetization in single-molecule magnets

Single-molecule magnets facilitate the study of quantum tunneling of magnetization at the mesoscopic level. The spin-parity effect is among the fundamental predictions that have yet to be clearly observed. It is predicted that quantum tunneling is suppressed at zero transverse field if the total spin of the magnetic system is half-integer (Kramers degeneracy) but is allowed in integer spin systems. The Landau-Zener method is used to measure the tunnel splitting as a function of transverse field. Spin-parity dependent tunneling is established by comparing the transverse field dependence of the tunnel splitting of integer and half-integer spin systems.

Spin-spin cross relaxation in single-molecule magnets

The one-body tunnel picture of single-molecule magnets (SMMs) is not always sufficient to explain the measured tunnel transitions. An improvement to the picture is proposed by including also two-body tunnel transitions such as spin-spin cross relaxation (SSCR) which are mediated by dipolar and weak superexchange interactions between molecules. A Mn4 SMM is used as a model system. At certain external fields, SSCRs lead to additional quantum resonances which show up in hysteresis loop measurements as well-defined steps. A simple model is used to explain quantitatively all observed transitions.

Landau-Zener tunneling in the presence of weak intermolecular interactions in a crystal of Mn-4 single-molecule magnets

A

Towards a synthetic model of the photosynthetic water oxidizing complex: [Mn3O4(O2CMe)4(bpy)2] containing the [MnIV3(μ-O)4]4+ core

{\mathrm{Mn}}_{4}

A comparative high frequency EPR study of monomeric and dimeric Mn 4 single-molecule magnets

single-molecule magnet (SMM), with a well-isolated spin ground state of

Half-Integer Spin Molecular Nanomagnets

S=9∕2

Two-body tunnel transitions in a Mn4 single-molecule magnet

, is used as a model system to study Landau-Zener (LZ) tunneling in the presence of weak intermolecular dipolar and exchange interactions. The anisotropy constants

Defects, Tunneling, and EPR Spectra of Single-Molecule Magnets

D

Sulfur bridging interactions of cis-planar NiII-S2N2 coordination units with nickel(II), copper(I, II), zinc(II), and mercury(II): A library of bridging modes, including NiII(μ2-SR)2MI, II rhombs

and

Symmetric and asymmetric dinuclear manganese(IV) complexes possessing a [MnIV2(μ-O)2(μ-O2CMe)]3+ core and terminal Cl- ligands

B