Magnetism of ultrathin Pd₉₉Fe₀₁films grown on niobium

Micromagnetic modeling of critical current oscillations in magnetic Josephson junctions

“…Yet, accurate micromagnetic simulation of magnetization reversal in the Pd 0.99 Fe 0.01 F layer can hardly be performed in the conventional manner due to the complex cluster nature of magnetism in Pd 0.99 Fe 0.01 [25]. The magnetic moment of the Pd 0.99 Fe 0.01 thin film is distributed mostly within the relatively large Fe-rich Pd 3 Fe nanoclusters of ∼10 nm size and ∼100 nm spacing in between.…”

“…[4,6,25] is justified by reorientation of the magnetic moment of these clusters. The paramagnetic host can be saturated only at high magnetic field H > 1-2 kOe [25] and, therefore, does not contribute to the M(H ) hysteresis dependence in our field of interest. In particular, typical hysteresis loops derived from experiments with Pd 0.99 Fe 0.01 -based MJJs do not demonstrate the paramagnetic component.…”

Ab initio Investigation of Impurity Ferromagnetism in the Pd1−xFex Alloys: Concentration and Position Dependences

“…The current revival of interest is fueled by the potential use as a material of a choice for a weak and soft ferromagnet in superconducting Josephson magnetic random-access memory (MRAM) based on Josephson junctions [4][5][6][7][8][9][10][11][12][13]. The Pd-rich ferromagnetic Pd 1−x Fe x (0.01 < x < 0.1) alloy is used there in the form of a thin film fabricated utilizing magnetron sputtering [5][6][7][8][9][10][11][13][14][15], molecular-beam epitaxy (MBE) [15][16][17][18][19][20][21][22][23], and ion-beam implantation [24].…”

“…There is a scatter of opinions on the compositional and magnetic homogeneity of Pd 1−x Fe x films obtained by different deposition techniques: some papers report an indication of clustering [10,11,13,14] or formation of the nanograins of the Pd 3 Fe phase [15] in samples deposited with the magnetron sputtering technique; the others on MBE growth of thin Pd 1−x Fe x films [18][19][20][21][22][23] report on their high magnetic homogeneity; finally, the ionimplanted palladium films [24] show a significant influence of the Fe implant distribution on saturation magnetization (M s ) and Curie temperature (T C ) of the samples. It is not clear why and how the redistribution of iron solute in the Pd matrix influences M s and T C .…”

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

“…However, no further developments towards a prototype using a Pd 1−x Fe x alloy have been demonstrated. There are indications of non-homogeneous, nanoclustered magnetism in Pd 0.99 Fe 0.01 films grown on niobium [31], which may cause a shortening of the spin-memory length [32] and a reduction of the Josephson critical current.…”