Modifying the properties of 4f single-ion magnets by peripheral ligand functionalisation

TY - JOUR

T1 - Modifying the properties of 4f single-ion magnets by peripheral ligand functionalisation

AU - Pedersen, Kasper Steen

AU - Ungur, Liviu

AU - Sigrist, Marc

AU - Sundt, Alexander

AU - Schau-Magnussen, Magnus

AU - Vieru, Veacheslav

AU - Mutka, Hannu

AU - Rols, Stephane

AU - Weihe, Høgni

AU - Waldmann, Oliver

AU - Chibotaru, Liviu F.

AU - Bendix, Jesper

AU - Dreiser, Jan

PY - 2014

Y1 - 2014

N2 - We study the ligand-field splittings and magnetic properties of three ErIII single-ion magnets which differ in the peripheral ligand sphere but exhibit similar first coordination spheres by inelastic neutron scattering (INS) and SQUID magnetometry. The INS spectra of the three compounds are profoundly different pointing at a strong response of the magnetic behavior to minor structural changes, as they are e.g. encountered when depositing molecules on surfaces. The observation of several magnetic excitations within the J = 15/2 ground multiplet together with single-crystal magnetic measurements allows for the extraction of the sign and magnitude of all symmetry-allowed Stevens parameters. The parameter values and the energy spectrum derived from INS are compared to the results of state-of-the-art ab initio CASSCF calculations. Temperature-dependent alternating current (ac) susceptibility measurements suggest that the magnetisation relaxation in the investigated temperature range of 1.9 K < T < 5 K is dominated by quantum tunnelling of magnetisation and two-phonon Raman processes. The possibility of observing electron paramagnetic resonance transitions between the ground-state doublet states, which can be suppressed in perfectly axial single-ion magnets, renders the studied systems interesting as representations of quantum bits.

AB - We study the ligand-field splittings and magnetic properties of three ErIII single-ion magnets which differ in the peripheral ligand sphere but exhibit similar first coordination spheres by inelastic neutron scattering (INS) and SQUID magnetometry. The INS spectra of the three compounds are profoundly different pointing at a strong response of the magnetic behavior to minor structural changes, as they are e.g. encountered when depositing molecules on surfaces. The observation of several magnetic excitations within the J = 15/2 ground multiplet together with single-crystal magnetic measurements allows for the extraction of the sign and magnitude of all symmetry-allowed Stevens parameters. The parameter values and the energy spectrum derived from INS are compared to the results of state-of-the-art ab initio CASSCF calculations. Temperature-dependent alternating current (ac) susceptibility measurements suggest that the magnetisation relaxation in the investigated temperature range of 1.9 K < T < 5 K is dominated by quantum tunnelling of magnetisation and two-phonon Raman processes. The possibility of observing electron paramagnetic resonance transitions between the ground-state doublet states, which can be suppressed in perfectly axial single-ion magnets, renders the studied systems interesting as representations of quantum bits.

U2 - 10.1039/c3sc53044b

DO - 10.1039/c3sc53044b

M3 - Journal article

AN - SCOPUS:84897583715

SN - 2041-6520

VL - 5

SP - 1650

EP - 1660

JO - Chemical Science

JF - Chemical Science

IS - 4

ER -