| Home | << 1 >> |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Sereni, J.G.; Gomez Berisso, M.; Braghta, A.; Schmerber, G.; Kappler, J.P. | ||||
Title  |
Unstable Shastry-Sutherland phase in Ce2Pd2Sn | Type | Journal Article | ||
| Year | 2008 | Publication | Physical Review B – Condensed Matter and Materials Physics | Abbreviated Journal | Phys. Rev. B |
| Volume | 80 | Issue | 2 | Pages | 022428 |
| Keywords | cerium alloys; crystal field interactions; entropy; ferromagnetic materials; frustration; magnetic anisotropy; magnetic hysteresis: magnetic transitions; palladium alloys; tin alloys | ||||
| Abstract | Thermal (CP) , magnetic ( M and χac ), and transport (Ï) measurements on Ce2Pd2Sn are reported. High-temperature properties are well described by the presence of two excited crystal-field levels at (65±5)K and (230±20)K , with negligible hybridization (Kondo) effects. According to literature, two transitions were observed at TM=4.8K and TC=2.1K , respectively. The upper transition cannot be considered as a standard antiferromagnetic because of frustration effects in a triangular network of Ce atoms and the positive sign of the paramagnetic temperature θPLT=4.4K . The nature of the intermediated phase is described accounting for the formation of ferromagnetic (F) Ce dimers disposed in a quasi-two-dimensional square lattice, resembling a Shastry-Sutherland pattern. According to hysteretic features in Ï(T) and χac(T) , the lower F transition is of first order, with CP(T<TC) revealing a gap of anisotropy Eg≈7K . | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Medium | |||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | BT @ pedrazp @ | Serial | 563 | ||
| Permanent link to this record | |||||
| Author | Franco, D.G.; Carbonio, R.E.; Nieva, G. | ||||
| Title |
Magnetic Properties of the Double Perovskites LaPbMSbO6 (M = Mn, Co, and Ni) | Type | Journal Article | ||
| Year | 2013 | Publication | IEEE Transactions on Magnetics | Abbreviated Journal | IEEE Trans. Magn. |
| Volume | 49 | Issue | 8 | Pages | 4594-4597 |
| Keywords | X-ray diffraction; cobalt compounds; lanthanum compounds; lead compounds; magnetisation; manganese compounds; nickel compounds; paramagnetic-antiferromagnetic transitions; space groups; superexchange interactions; LaPbCoSbO6; LaPbMnSbO6; LaPbNiSbO6; M2+ distribution; Rietveld analysis; Sb5+ distribution; X-ray powder diffraction pattern; antiferromagnetic coupling; antiferromagnetic transition; aqueous synthetic route; disorder; double perovskites; ferrimagnetic characteristics; interaction paths; magnetic ions; magnetic properties; monoclinic crystals; octahedral sites; polycrystals; space group P2 1/n; super-superexchange paths; Ions; Magnetic properties; Magnetization; Manganese; Nickel; Temperature measurement; X-ray diffraction; Antiferromagnetic materials; transition metal compounds | ||||
| Abstract | New double perovskites LaPbMSbO6, where M2+ = Mn2+, Co2+, and Ni2+, were synthesized as polycrystals by an aqueous synthetic route at temperatures below 1000 °C. All samples are monoclinic, space group P21/n, as it is observed from Rietveld analysis of X-ray powder diffraction patterns. The distribution of M2+ and Sb5+ among the two octahedral sites have 3% of disorder for M2+ = Ni2+, whereas for M2+ = Mn2+ and Co2+ less disorder is found. The three samples have an antiferromagnetic transition, due to the antiferromagnetic coupling between M2 + through super-superexchange paths M2+-O2--Sb5+-O2--M2+. Transition temperatures are low: 8, 10 and 17 K for Mn2+, Co2+, and Ni2 + respectively, as a consequence of the relatively long distances between the magnetic ions M2+. Besides, for LaPbMnSbO6 a small transition at 45 K was found, with ferrimagnetic characteristics, possibly as a consequence of a small disorder between Mn2+ and Sb5+. This disorder would give additional and shorter interaction paths: superexchange Mn2+-O2--Mn2+. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0018-9464 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | BT @ pedrazp @ | Serial | 669 | ||
| Permanent link to this record | |||||
| Author | Deppe, M.; Caroca-Canales, N.; Sereni, J.G.; Geibel, C. | ||||
| Title |
Evidence for a metamagnetic transition in the heavy Fermion system CeTiGe | Type | Conference Article | ||
| Year | 2010 | Publication | Journal of Physics: Conference Series | Abbreviated Journal | J. Phys.: Conf. Ser. |
| Volume | 200 | Issue | Pages | 012026 | |
| Keywords | Applied magnetic fields; Canonical systems; Continuous suppression; Critical behavior; Critical fields; DC magnetization; First order; Heavy fermion systems; Higher temperatures; Low temperatures; Metamagnetic; Metamagnetic transitions; Polycrystalline; Cerium; Cerium compounds; Electric resistance; Magnetic field effects; Magnetoresistance; Magnetism | ||||
| Abstract | A recent study of CeTiGe identified this compound as a paramagnetic heavy Fermion system where the full J = 5/2 multiplet is involved in the formation of the ground state. Here we present a preliminary investigation of the dc-magnetization Mdc(H) and of the magnetoresistance Ï(H) of polycrystalline CeTiGe samples in applied magnetic fields up to μ0H = 14 T. The results reveal a pronounced metamagnetic transition at a critical field μ0Hc ≈ 13.5 T at low temperatures, with a step like increase in Mdc(H) of at least 0.6 μB/Ce. The metamagnetic transition leads to a strong decrease in Ï(H). A clear hysteresis in Mdc(H) and Ï(H) indicate that in CeTiGe these metamagnetic features correspond to a true thermodynamic, first order type transition in contrast to the critical behavior observed in the canonical system CeRu2Si2. Measurements at higher temperatures showed a continuous suppression of the metamagnetic transition with increasing T, which vanishes at T ∼ 30 K. © 2010 IOP Publishing Ltd. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Karlsruhe | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | International Conference on Magnetism, ICM 2009 | Abbreviated Series Title | ||
| Series Volume | 200 | Series Issue | SECTION 1 | Edition | |
| ISSN | 17426588 (ISSN) | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Conference code: 81773; Export Date: 10 December 2010; Source: Scopus; Art. No.: 012026; doi: 10.1088/1742-6596/200/1/012026; Language of Original Document: English; Correspondence Address: Deppe, M.; Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany; email: Hicha.Deppe@cpfs.mpg.de; References: Gegenwart, P., Si, Q., Steglich, F., (2008) Nature Phys., 4 (3), p. 186; Sachdev, S., (2008) Nature Phys., 4 (3), p. 173; Blundell, S., (2001) Oxford Master Series in Condensed Matter Physics, , (Oxford University Press); Monthoux, P., Lonzarich, G.G., (2001) Phys. Rev., 63 (5), p. 054529; Morozkin, A.V., Seropegin Yu, D., Leonov, A.V., Sviridov, I.A., Tskhadadze, I.A., Nikitin, S.A., (1998) J. Alloys Comput., 267, pp. 14-15R; Welter, R., Vernière, A., Venturini, G., Malaman, B., (1999) J. Alloys. Compounds, 283 (1-2), p. 54; Deppe, M., Caroca-Canales, N., Hartmann, S., Oeschler, N., Geibel, C., (2009) J. Phys.: Condens. Matter, 21 (20), p. 206001; Hewson, A.C., (1993) The Kondo Problem to Heavy Fermions (Cambridge Studies in Magnetism), 2. , ed D Edwards and D Melville (Cambridge: Cambridge University press); Haen, P., Flouquet, J., Lapierre, F., Lejay, P., Remenyi, G., (1987) J. Low Temp. Phys., 67 (5-6), p. 391; Sakakibara, T., Tayama, T., Matamura, K., Maezawa, K., Onuki, Y., Amitsuka, H., (1995) Phys. Rev., 51 (17), p. 12030; Andreev, A.V., Vejpravov, J., Prokleška, J., Sechovsky, V., (2008) Physica, 403 (5-9), p. 744 | Approved | no | ||
| Call Number | BT @ berisso @ | Serial | 599 | ||
| Permanent link to this record | |||||
| Author | Franco, D.G.; Carbonio, R.E.; Nieva, G. | ||||
| Title |
Change in the Magnetic Domain Alignment Process at the Onset of a Frustrated Magnetic State in Ferrimagnetic La2Ni(Ni1/3Sb2/3)O6 Double Perovskite | Type | Journal Article | ||
| Year | 2013 | Publication | IEEE Transactions on Magnetics | Abbreviated Journal | IEEE Trans. Magn. |
| Volume | 49 | Issue | 8 | Pages | 4656-4659 |
| Keywords | coercive force; exchange interactions (electron); ferrimagnetic materials; frustration; magnetic domain walls; magnetic hysteresis; magnetic transitions; LaNi(Ni0.33Sb0.67)O6; applied magnetic field; coercive field; domain wall pinning; ferrimagnetic double perovskite; ferrimagnetic order transition; frustrated magnetic state; hysteresis data; low temperature regime; magnetic domain alignment process; magnetic exchange interactions; magnetization hysteresis loops; temperature dependence; Magnetic domain walls; Magnetic domains; Magnetic hysteresis; Magnetization; Nickel; Temperature distribution; Temperature measurement; Ferrimagnetic materials; magnetic analysis; magnetic domain walls; magnetic hysteresis | ||||
| Abstract | We have performed a combined study of magnetization hysteresis loops and time dependence of the magnetization in a broad temperature range for the ferrimagnetic La2Ni(Ni1/3Sb2/3)O6 double perovskite. This material has a ferrimagnetic order transition at ~100 K and at lower temperatures (~20 K) shows the signature of a frustrated state due to the presence of two competing magnetic exchange interactions. The temperature dependence of the coercive field shows an important upturn below the point where the frustrated state sets in. The use of hysteresis data, magnetization versus applied magnetic field, together with the magnetization versus time data provides a unique opportunity to distinguish between different scenarios for the low temperature regime. From our analysis, a strong domain wall pinning results in the best scenario for the low temperature regime. For temperatures larger than 20 K, the adequate scenario seems to correspond to a weak domain wall pinning. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0018-9464 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | BT @ pedrazp @ | Serial | 668 | ||
| Permanent link to this record | |||||