NdFeB thin films possessing high coercivity and perpendicular anisotropy were prepared with high reproducibility by means of RF sputtering deposition on Mo substrates with subsequent annealing ...treatment. The use of glass thermal insulation between the substrates and substrate holder during deposition made it possible to produce films with improved magnetic properties. The development of the magnetic properties were then found to have some dependence on the thickness of glass insulation making such films a realization of thin film permanent magnets with magnetic field strength comparable to bulk processed magnets. The magnetic properties dependence on the thickness (t) of glass insulation has revealed the following data: Film prepared without insulation produced a randomly oriented film with coercivity (iHc) around 480 kA/m, remanence value (Mr) around 0.67 T, MrMs=0.48 and (BH) max around 73 kJ/m3. While on the other hand, the films on substrates with insulation thickness of t=0.1, 0.2, 0.3, 0.6, 0.8 and 1.3 mm, magnetic properties of 4πMr= 0.67-0.93 T, iHc=1082-1290 kA/m, Mr/Ms=0.52-0.96 and a (BH) max=80-167 kJ/m3, were found.
Magnetooptical measurements of a quasi-two-dimensional (q2D) organic
conductor (BEDT-TTF)2Br(DIA) (DIA=diiodoacetylene) were performed using a
cavity perturbation technique with a millimeter vector ...network analyzer (MVNA).
Harmonic resonances were observed periodically as a function of the inverse
field up to the 7th order. This is the first observation of higher-order
harmonics up to the 7th order in an organic conductor. The observed resonance
is assigned as a periodic orbit resonance (POR) which arises from a q2D
elliptic Fermi surface (FS). The obtained effective mass (4.7me) is consistent
with Shubnikov-de Haas measurements. Temperature dependence of the spectra
observed in two different sample configurations will be presented.
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