--- _id: '7056' abstract: - lang: eng text: "In the Ca1−x La x FeAs2 (1 1 2) family of pnictide superconductors, we have investigated a highly overdoped composition (x  =  0.56), prepared by a high-pressure, high-temperature synthesis. Magnetic measurements show an antiferromagnetic transition at T N  =  120 K, well above the one at lower doping (0.15  <  x  <  0.27).\r\n\r\nBelow the onset of long-range magnetic order at T N, the electrical resistivity is strongly reduced and is dominated by electron–electron interactions, as evident from its temperature dependence. The Seebeck coefficient shows a clear metallic behavior as in narrow band conductors. The temperature dependence of the Hall coefficient and the violation of Kohler's rule agree with the multiband character of the material. No superconductivity was observed down to 1.8 K. The success of the high-pressure synthesis encourages further investigations of the so far only partially explored phase diagram in this family of Iron-based high temperature superconductors.\r\n" article_number: '485705' article_processing_charge: No article_type: original author: - first_name: Edoardo full_name: Martino, Edoardo last_name: Martino - first_name: Maja D full_name: Bachmann, Maja D last_name: Bachmann - first_name: Lidia full_name: Rossi, Lidia last_name: Rossi - first_name: Kimberly A full_name: Modic, Kimberly A id: 13C26AC0-EB69-11E9-87C6-5F3BE6697425 last_name: Modic orcid: 0000-0001-9760-3147 - first_name: Ivica full_name: Zivkovic, Ivica last_name: Zivkovic - first_name: Henrik M full_name: Rønnow, Henrik M last_name: Rønnow - first_name: Philip J W full_name: Moll, Philip J W last_name: Moll - first_name: Ana full_name: Akrap, Ana last_name: Akrap - first_name: László full_name: Forró, László last_name: Forró - first_name: Sergiy full_name: Katrych, Sergiy last_name: Katrych citation: ama: 'Martino E, Bachmann MD, Rossi L, et al. Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2. Journal of Physics: Condensed Matter. 2019;31(48). doi:10.1088/1361-648x/ab3b43' apa: 'Martino, E., Bachmann, M. D., Rossi, L., Modic, K. A., Zivkovic, I., Rønnow, H. M., … Katrych, S. (2019). Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2. Journal of Physics: Condensed Matter. IOP Publishing. https://doi.org/10.1088/1361-648x/ab3b43' chicago: 'Martino, Edoardo, Maja D Bachmann, Lidia Rossi, Kimberly A Modic, Ivica Zivkovic, Henrik M Rønnow, Philip J W Moll, Ana Akrap, László Forró, and Sergiy Katrych. “Persistent Antiferromagnetic Order in Heavily Overdoped Ca1−x La x FeAs2.” Journal of Physics: Condensed Matter. IOP Publishing, 2019. https://doi.org/10.1088/1361-648x/ab3b43.' ieee: 'E. Martino et al., “Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2,” Journal of Physics: Condensed Matter, vol. 31, no. 48. IOP Publishing, 2019.' ista: 'Martino E, Bachmann MD, Rossi L, Modic KA, Zivkovic I, Rønnow HM, Moll PJW, Akrap A, Forró L, Katrych S. 2019. Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2. Journal of Physics: Condensed Matter. 31(48), 485705.' mla: 'Martino, Edoardo, et al. “Persistent Antiferromagnetic Order in Heavily Overdoped Ca1−x La x FeAs2.” Journal of Physics: Condensed Matter, vol. 31, no. 48, 485705, IOP Publishing, 2019, doi:10.1088/1361-648x/ab3b43.' short: 'E. Martino, M.D. Bachmann, L. Rossi, K.A. Modic, I. Zivkovic, H.M. Rønnow, P.J.W. Moll, A. Akrap, L. Forró, S. Katrych, Journal of Physics: Condensed Matter 31 (2019).' date_created: 2019-11-19T12:56:17Z date_published: 2019-09-03T00:00:00Z date_updated: 2021-01-12T08:11:35Z day: '03' doi: 10.1088/1361-648x/ab3b43 extern: '1' external_id: arxiv: - '1905.08640' intvolume: ' 31' issue: '48' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1905.08640 month: '09' oa: 1 oa_version: Preprint publication: 'Journal of Physics: Condensed Matter' publication_identifier: eissn: - 1361-648X issn: - 0953-8984 publication_status: published publisher: IOP Publishing quality_controlled: '1' status: public title: Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 31 year: '2019' ... --- _id: '7076' abstract: - lang: eng text: Iron is a ubiquitous impurity in metamict (radiation-damaged and partially amorphized) materials such as titanite (CaSiTiO5). Using 57Fe Mössbauer spectroscopy we find that iron in metamict titanite is partitioned between amorphous and crystalline regions based on valence. Trivalent iron exists in the crystalline titanite matrix whereas divalent iron exists almost exclusively in radiation-amorphized regions. We find that the relative abundances of the oxidation states correlate with the volume fraction of amorphous and crystalline regions. Our data also show that oxidation of iron proceeds along with the recrystallization of the amorphized regions. Recrystallization is confirmed to occur over the range 700 °C < T < 925 °C, and no further structural changes are observed at higher temperatures. It is surprising that our Mössbauer measurements show divalent iron to be surrounded by titanite with a high degree of short-range structural order in the amorphized regions. This observation is fundamentally different from other metamict materials such as zircon (ZrSiO4), where amorphized regions show no short-range order. article_number: '105402' article_processing_charge: No article_type: original author: - first_name: E K H full_name: Salje, E K H last_name: Salje - first_name: D J full_name: Safarik, D J last_name: Safarik - first_name: R D full_name: Taylor, R D last_name: Taylor - first_name: M P full_name: Pasternak, M P last_name: Pasternak - first_name: Kimberly A full_name: Modic, Kimberly A id: 13C26AC0-EB69-11E9-87C6-5F3BE6697425 last_name: Modic orcid: 0000-0001-9760-3147 - first_name: L A full_name: Groat, L A last_name: Groat - first_name: J C full_name: Lashley, J C last_name: Lashley citation: ama: 'Salje EKH, Safarik DJ, Taylor RD, et al. Determination of iron sites and the amount of amorphization in radiation-damaged titanite (CaSiTiO5). Journal of Physics: Condensed Matter. 2011;23(10). doi:10.1088/0953-8984/23/10/105402' apa: 'Salje, E. K. H., Safarik, D. J., Taylor, R. D., Pasternak, M. P., Modic, K. A., Groat, L. A., & Lashley, J. C. (2011). Determination of iron sites and the amount of amorphization in radiation-damaged titanite (CaSiTiO5). Journal of Physics: Condensed Matter. IOP Publishing. https://doi.org/10.1088/0953-8984/23/10/105402' chicago: 'Salje, E K H, D J Safarik, R D Taylor, M P Pasternak, Kimberly A Modic, L A Groat, and J C Lashley. “Determination of Iron Sites and the Amount of Amorphization in Radiation-Damaged Titanite (CaSiTiO5).” Journal of Physics: Condensed Matter. IOP Publishing, 2011. https://doi.org/10.1088/0953-8984/23/10/105402.' ieee: 'E. K. H. Salje et al., “Determination of iron sites and the amount of amorphization in radiation-damaged titanite (CaSiTiO5),” Journal of Physics: Condensed Matter, vol. 23, no. 10. IOP Publishing, 2011.' ista: 'Salje EKH, Safarik DJ, Taylor RD, Pasternak MP, Modic KA, Groat LA, Lashley JC. 2011. Determination of iron sites and the amount of amorphization in radiation-damaged titanite (CaSiTiO5). Journal of Physics: Condensed Matter. 23(10), 105402.' mla: 'Salje, E. K. H., et al. “Determination of Iron Sites and the Amount of Amorphization in Radiation-Damaged Titanite (CaSiTiO5).” Journal of Physics: Condensed Matter, vol. 23, no. 10, 105402, IOP Publishing, 2011, doi:10.1088/0953-8984/23/10/105402.' short: 'E.K.H. Salje, D.J. Safarik, R.D. Taylor, M.P. Pasternak, K.A. Modic, L.A. Groat, J.C. Lashley, Journal of Physics: Condensed Matter 23 (2011).' date_created: 2019-11-19T13:39:30Z date_published: 2011-02-21T00:00:00Z date_updated: 2021-01-12T08:11:43Z day: '21' doi: 10.1088/0953-8984/23/10/105402 extern: '1' intvolume: ' 23' issue: '10' language: - iso: eng month: '02' oa_version: None publication: 'Journal of Physics: Condensed Matter' publication_identifier: issn: - 0953-8984 - 1361-648X publication_status: published publisher: IOP Publishing quality_controlled: '1' status: public title: Determination of iron sites and the amount of amorphization in radiation-damaged titanite (CaSiTiO5) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 23 year: '2011' ...