Structural anomalies and multiferroic behavior in magnetically frustrated TbMn2O5.
Phys Rev Lett 93:17 (2004) 177402
Abstract:
We have studied the magnetostructural phase diagram of multiferroic TbMn2O5 as a function of temperature and magnetic field by neutron diffraction. Dielectric and magnetic anomalies are found to be associated with steps in the magnetic propagation vector, including a rare example of a commensurate-incommensurate transition on cooling below 24 K, and in the structural parameters. The geometrically frustrated magnetic structure is stabilized by "canted antiferroelectric" displacements of the Mn3+ ions, an example of the magnetic Jahn-Teller effect. The Tb moments order ferromagnetically at low temperatures in an applied field, while the Mn magnetic structure is largely unchanged.Diffraction probes of charge and orbital ordering: from perovskites to geometrically frustrated systems
Acta Crystallographica Section A: Foundations and advances International Union of Crystallography (IUCr) 60:a1 (2004) s58-s58
Structural aspects of metamagnetism in Ca_{2-x}Sr_{x}RuO_4 (0.2 < x < 0.5): field tuning of orbital occupation
(2004)
Structural aspects of metamagnetism in Ca_{2-x}Sr_{x}RuO_4 (0.2 < x < 0.5): field tuning of orbital occupation
ArXiv cond-mat/0408015 (2004)
Abstract:
The crystal structure of Ca_{2-x}Sr_xRuO_4 with 0.2 < x < 1.0 has been studied by diffraction techniques and by high resolution capacitance dilatometry as a function of temperature and magnetic field. Upon cooling in zero magnetic field below about 25 K the structure shrinks along the c-direction and elongates in the a, b planes (0.2 < x < 1.0), whereas the opposite occurs upon cooling at high-field (x = 0.2 and 0.5). These findings indicate an orbital rearrangement driven by temperature and magnetic field, which accompanies the metamagnetic transition in these compounds.The structure of intercalated water in superconducting Na$_{0.35}$CoO$_{2}\cdot$1.37D$_{2}$O: Implications for the superconducting phase diagram
(2004)