The azafullerene Tb 2 @C 79 N is found to be a single‐molecule magnet with a high 100‐s blocking temperature of magnetization of 24 K and large coercivity. Tb magnetic moments with an easy‐axis single‐ion magnetic anisotropy are strongly coupled by the unpaired spin of the single‐electron Tb−Tb bond. Relaxation of magnetization in Tb 2 @C 79 N below 15 K proceeds via quantum tunneling of magnetization with the characteristic time τ QTM =16 462±1230 s. At higher temperature, relaxation follows the Orbach mechanism with a barrier of 757±4 K, corresponding to the excited states, in which one of the Tb spins is flipped.

Investigations into fast magnetization switching are of both fundamental and technological interest. Here we present a low-power, remote method for strain driven magnetization switching. A surface acoustic wave propagates across an array of ferromagnetic elements, and the resultant strain switches the magnetization from the easy axis into the hard axis direction. Investigations as a function of applied magnetic field as well as unidirectional anisotropy (the exchange bias) reveal excellent agreement with prediction, confirming the viability of this method.

A high frequency (88 MHz) traveling strain wave on a piezoelectric substrate is shown to change the magnetization direction in 40 lm wide Co bars with an aspect ratio of 10 3 . The rapidly alternating strain wave rotates the magnetization away from the long axis into the short axis direction, via magnetoelastic coupling. Strain-induced magnetization changes have previously been demonstrated in ferroelectric/ferromagnetic heterostructures, with excellent fidelity between the ferromagnet and the ferroelectric domains, but these experiments were limited to essentially dc frequencies. Both magneto-optical Kerr effect and polarized neutron reflectivity confirm that the traveling strain wave does rotate the magnetization away from the long axis direction and both yield quantitatively similar values for the rotated magnetization. An investigation of the behavior of short axis magnetization with increasing strain wave amplitude on a series of samples with variable edge roughness suggests that the magnetization reorientation that is seen proceeds solely via coherent rotation. Polarized neutron reflectivity data provide direct experimental evidence for this model. This is consistent with expectations that domain wall motion cannot track the rapidly varying strain. V C 2015 AIP Publishing LLC. [http://dx

Endohedral metallofullerenes and, in particular, trimetallic nitride endohedral metallofullerenes exhibit unique properties that differentiate them from other carbon nanomaterials. Future applications of these species are restricted due to high cost and low productivity of existing synthesis methods, which are primarily based on the use of a Kr€ atschmer-Huffman two electrode in-line arc discharge reactor with packed electrodes. We have developed an alternative way for the synthesis of metallofullerenes that employs a 3-phase arc discharge system. The method has been validated and optimized for the synthesis of trimetallic nitride endohedral metallofullerenes, including Lu 3 N@C 80 . Experimental results have shown more than 400% increase in Lu 3 N@C 80 yield and productivity, while eliminating the use of high cost process gases (i.e., helium). Moreover, a metal oxide powder feed and solid graphite electrodes are introduced to avoid the need for packed electrodes and to extend reactor run times.

Das Azafulleren Tb 2 @C 79 Nw ird als Einzelmolekülmagnet mit einer hohen 100-s-Block-Temperatur der Magnetisierung von 24 Ku nd hoher Koerzitivfeldstärke identifiziert. Die magnetischen Momente von Tb mit magnetischer Vorzugsachsen-Anisotropie sind durchd en ungepaarten Spin der Einelektronenbindung stark gekoppelt. Die Relaxation der Magnetisierung findet in Tb 2 @C 79 Nb ei Temperaturen unter 15 Kd urch Quantentunneln der Magnetisierung mit einer charakteristischen Relaxationszeit von t QTM = 16 462 AE 1230 s statt. Bei hçheren Temperaturen folgt die Relaxation dem Orbach-Mechanismus mit einer Barriere von 757 AE 4K,w as dem angeregten Zustand entspricht, in dem einer der Tb-Spins umgekehrt wird.