An Investigation of the Magnetic and Electronic Properties of Mn Oxypnictides

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An Investigation of the Magnetic and Electronic Properties of Mn Oxypnictides A. C. Mclaughlin, University of Aberdeen Abstract Iron oxypnictides have been attracting much attention since the discovery of high temperature superconductivity in LnFeAsO 1-x F x 1 . We will present research on the crystal structure, magnetic and electronic properties of several Mn oxypnictides which evidence a plethora of interesting behaviour. Antiferromagnetic order is observed in LnMnAsO below  360 K with a spin reorientation transition at low temperature when the Ln order antiferromagnetically (Ln = Nd, Pr, Ce) 2-5 . Sizeable negative magnetoresistance is observed upon electron doping LnMnAsO 1-x F x (Ln = Nd, Pr) with MRs up to - 95% at 4 K 5 . A novel insulator-insulator transition is observed upon electron doping the Mott insulator CeMnAsO. The resistivity increases by more than two orders of magnitude over a 2 K temperature range and the transition temperature can be tuned by increasing x. Finally, we have started to investigate more complex oxypnictides such as Sr 2 Mn 2 CrAs 2 O 2 (Fig. 1) which exhibits magnetic phase segregation below 160 K. Fig. 1 Crystal structure of Sr 2 Mn 2 CrAs 2 O 2 References 1. Kamihara, Y.; Watanabe, T.; Hirano, M. & Hosono, H. J. Amer. Chem. Soc. 2008, 130 , 3296-3297. 2. Emery, N.; Wildman, E. J; Skakle, J. M. S.; Mclaughlin, A. C.; Smith, R. I. & Fitch, A. N. Phys. Rev. B , 2011, 83 , 144429. 3. Wildman, E. J. & Mclaughlin, A. C. Sci. Rep. 2016, 6 , 20705. 4. Wildman, E. J.; Sher, F. & Mclaughlin, A. C. Inorg. Chem. 2015, 54 , 2536-2542. 5. Wildman, E. J.; Skakle, J. M. S.; Emery, N. & Mclaughlin, A. C. J. Amer. Chem. Soc. 2012, 134 , 8766- 8769. Download PDF

  • Speaker

    Abbie Mclaughlin
    University of Aberdeen

  • Venue

    222, Physics

  • Date

    October 9, 2019

  • Time

    From: 12h00 To: 13h00

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