X‐Ray Detected Magnetic Hysteresis of Thermally Evaporated Terbium Double‐Decker Oriented Films

Abstract

Successful attempts to deposit SMMs in UHV conditions\ud have been carried out with a tetranuclear iron(III) cluster [ 9 ]\ud and lanthanide bis-phthalocyaninato (LnPc 2 ) complexes. [ 10 , 11 ]\ud For the latter the seminal works of Ishikawa et al. [ 12 ] showed\ud that slow dynamics of the magnetization in these mononuclear\ud complexes is originated directly from their strong single ion\ud anisotropy. Very recently a structural and magnetic characterization\ud of a sub-monolayer deposit TbPc 2 based on synchrotronlight\ud techniques has confi rmed that this magnetic anisotropy is\ud retained on surface. [ 13 ] The absence of the observation of typical\ud slow dynamics of the magnetization has been attributed to the\ud long time-scale of the X-ray based experiments.\ud We report here a synchrotron-based investigation on neutral\ud TbPc 2 evaporated thick and thin fi lms evidencing that the thick\ud fi lm of TbPc 2 is characterized by slow relaxation of the magnetization\ud and opening of a butterfl y hysteresis cycle at temperatures\ud as high as 15 K but not observed for the thin fi lm. These\ud differences are accompanied with a drastic change in the orientation\ud of the TbPc 2 molecules in the two fi lm

Radical ligand-containing single-molecule magnets

“…For instance, variations of TbPc 2 have been deposited onto pyrolytic graphite [234][235][236], graphene [237,238], carbon nanotubes [239], copper (1 0 0) [240], copper (1 1 1) [241], ferro-magnetic films [242], gold films [243], gold (1 1 1) [244,245]. Interactions of TbPc 2 with single-walled nanotubes (SWNTs) [239,246], within the context of potential molecular spintronic devices have further been reported [247,248].…”

Molecular lanthanide single-ion magnets: from bulk to submonolayers

“…Magnetic hysteresis of a thick (left double panel) and a thin (right) film of TbPc 2 on Au (1 1 1). Reproduced with permission from [162].…”

X-ray induced demagnetization of single-molecule magnets

“…There is growing interest in x-ray magnetic circular dichroism (XMCD) to study SMMs because of its ability to detect element-resolved magnetic moments combined with submonolayer sensitivity. [9][10][11][12][13][14] XMCD has been used to observe magnetic hysteresis, i.e., nonequilibrium magnetization in SMMs. [11][12][13] Here, we demonstrate that in endohedral SMMs the x-ray exposure itself can lead to an acceleration of magnetization relaxation.…”

“…[9][10][11][12][13][14] XMCD has been used to observe magnetic hysteresis, i.e., nonequilibrium magnetization in SMMs. [11][12][13] Here, we demonstrate that in endohedral SMMs the x-ray exposure itself can lead to an acceleration of magnetization relaxation. The x-ray induced demagnetization can be understood by the creation of small volumes of excited, or hot, molecules by the secondary electrons emitted from the Auger decay of the x-ray induced core hole.…”