Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 58: Multiferroics II (organized by MA)

TT 58.8: Talk

Wednesday, April 2, 2014, 11:30–11:45, HSZ 04

Magnetic Anisotropy in Multiferroic Lu₂MnCoO₆ — •Martin Lonsky¹, Merlin Pohlit¹, María Antonia Señarís Rodríguez², and Jens Müller¹ — ¹Physikalisches Institut, Goethe-Universität, Frankfurt (M), Germany — ²Dpto. Química Fundamental U. Coruña, Coruña, Spain

Lu₂MnCoO₆ recently has been introduced as a new type-II multiferroic with ferroelectricity due to charge ordering and magnetostriction related to magnetic Mn⁴⁺ and Co²⁺ ions which are arranged alternately in the form of Ising chains along the c-axis of the crystal [1]. The magnetic properties, however, remain puzzling, which in particular is due to the lack of measurements on single crystals, that have not yet successfully been synthesized. Here, we present for the first time measurements of the magnetic anisotropy by employing micro-Hall magnetometry on a few micrograins of dimensions ∼ 1   µ m only. Our results reveal a strong dependence of magnetic hysteresis on temperature and the applied field direction. This anisotropy is also reflected in the observation of a variety of unusual effects as for instance wasp-waisted hysteresis loops, sharp jumps in magnetization at about T=300 mK and an exchange bias, ocurring in each case in only one field direction. Additionally, the observation of a pronounced maximum in the coercive field at T_SF ∼ 12 K indicates a significant change in the spin dynamics of the system below T_SF, similar to the behavior of the related compound Ca₃Co_2−xMn_xO₆ (x≈0.95) [2].
S. Yáñez-Vilar et al., Phys. Rev. B. 84, 134427 (2011).
T. Lancaster et al., Phys. Rev. B 80, 020409 (2009).