Epitaxial ferromagnetic samarium and samarium silicide synthesized on Si(001)

Costescu, Ruxandra M.; Gheorghe, Nicoleta; Husanu, Marius-Adrian; Lungu, George A.; Macovei, D.; Pintilie, I.; Popescu, D.; Teodorescu, Cristian M.

doi:10.1007/s10853-012-6672-z

Cited by 25 publications

(12 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous quantitative analyses when using these factors have given reasonable results, applied to our setup [45,48,49,61]. Only for rare earths had these ASF to be slightly adjusted [22,23]. It may also be observed that the results obtained by using Ge 2p and Ge 3d do not deviate that much.…”

Section: Resultssupporting

confidence: 62%

See 1 more Smart Citation

Room Temperature Ferromagnetic Mn:Ge(001)

et al. 2013

View full text Add to dashboard Cite

We report the synthesis of a room temperature ferromagnetic Mn-Ge system obtained by simple deposition of manganese on Ge(001), heated at relatively high temperature (starting with 250 °C). The samples were characterized by low energy electron diffraction (LEED), scanning tunneling microscopy (STM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), superconducting quantum interference device (SQUID), and magneto-optical Kerr effect (MOKE). Samples deposited at relatively elevated temperature (350 °C) exhibited the formation of ~5–8 nm diameter Mn5Ge3 and Mn11Ge8 agglomerates by HRTEM, while XPS identified at least two Mn-containing phases: the agglomerates, together with a Ge-rich MnGe~2.5 phase, or manganese diluted into the Ge(001) crystal. LEED revealed the persistence of long range order after a relatively high amount of Mn (100 nm) deposited on the single crystal substrate. STM probed the existence of dimer rows on the surface, slightly elongated as compared with Ge–Ge dimers on Ge(001). The films exhibited a clear ferromagnetism at room temperature, opening the possibility of forming a magnetic phase behind a nearly ideally terminated Ge surface, which could find applications in integration of magnetic functionalities on semiconductor bases. SQUID probed the co-existence of a superparamagnetic phase, with one phase which may be attributed to a diluted magnetic semiconductor. The hypothesis that the room temperature ferromagnetic phase might be the one with manganese diluted into the Ge crystal is formulated and discussed.

show abstract

Section: Resultssupporting

confidence: 62%

“…The system is described in greater detail in references [22,24]. The base pressure in all ultrahigh vacuum (UHV) chambers is in the low 10 −10 mbar to 10 −11 vacuum range.…”

Section: Methodsmentioning

confidence: 99%

Room Temperature Ferromagnetic Mn:Ge(001)

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The deconvolution parameters are summarized in Table 1. In identifying the nature of the compounds formed at the surface, we take advantage of the following: (i) no contaminants (C, N, O, ...) are observed in the survey spectra; (ii) it is natural to associate the lowest BE Si 2p component to Sm silicide, with the highest possible amount of Sm; (iii) it is also natural to attribute the highest BE Sm 3d component to a Sm silicide; (iv) the Sm 3d component of lowest BE (~ 1074 eV) disappears when the sample is measured for several hours in UHV, therefore it may be attributed to metal Sm [24]; (v) the highest BE Sm 3d component may be attributed to Sm 3+ , as results from the comparison with the Sm 2 O 3 spectrum; (vi) finally, no band bending was observed by measuring the valence band spectra. The data interpretation is consistent with most assignments on RE reacted with Si(001) reported in Ref.…”

Section: Methodsmentioning

confidence: 99%

Structure, reactivity, electronic configuration and magnetism of samarium atomic layers deposited on Si(001) by molecular beam epitaxy

Gheorghe

Lungu

Husanu

et al. 2013

Applied Surface Science

Self Cite

View full text Add to dashboard Cite

The surface structure, interface reactivity, electron configuration and magnetic properties of Sm layers deposited on Si(001) at various temperatures are investigated by low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and magneto-optical Kerr effect (MOKE). It is found that metal Sm is present on samples prepared at low temperature, with an interface layer containing SmSi 2 and Sm 4 Si 3. When samples are prepared at high temperature, much less metal Sm is found, with an increasing amount of SmSi 2. Room temperature ferromagnetism is observed for all prepared layers, with a decrease of the saturation magnetisation when samples are prepared at high temperature. It is found that ferromagnetism implies mostly a compound with approximate stoichiometry Sm 4 Si 3. Also, the decrease in the intensity of the XAS 2p 3/2 → 3d white lines with the corresponding increasing amount of SmSi 2 may be explained by assuming a higher occupancy of Sm 5d orbitals (5d 2 configuration), most probably due to hybridation effects.

show abstract

“…14,15 As shown in figure 5d, the two peaks correspond to the characteristic Sm 3d 5/2 and Sm 3d 3/2 signals. [16][17][18] No evidence of other oxidation states of samarium was found. 19 But the binding energy for Sm 3d 5/2 is 1083.4 eV in Sm 2 O 3 (Sm-O bonds), 17 which is little different from Sm 3d 5/2 in P 3 .…”

Section: Resultsmentioning

confidence: 99%

One-step synthesis of samarium-doped ceria and its CO catalysis

et al. 2015

View full text Add to dashboard Cite

The samarium-doped ceria (SDC) nanospheres were prepared by the one-step hydrothermal method and characterized by transmission electron microscope, scanning electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectrometer and Raman spectra. According to the results, samarium was doped into the lattice successfully. The as-prepared samples were dispersed well and the average diameter was 60 nm. It showed better catalytic performance than pure ceria and the most appropriate concentration of doping was found.

show abstract

Epitaxial ferromagnetic samarium and samarium silicide synthesized on Si(001)

Cited by 25 publications

References 45 publications

Room Temperature Ferromagnetic Mn:Ge(001)

Room Temperature Ferromagnetic Mn:Ge(001)

Structure, reactivity, electronic configuration and magnetism of samarium atomic layers deposited on Si(001) by molecular beam epitaxy

One-step synthesis of samarium-doped ceria and its CO catalysis

Contact Info

Product

Resources

About