Blai Casals, Rafael Cichelero, Pablo García Fernández, Javier Junquera, David Pesquera, Mariano Campoy-Quiles, Ingrid C. Infante, Florencio Sánchez, Josep Fontcuberta, and Gervasi Herranz. Phys. Rev. Lett. 117, 026401 – Published 7 July 2016. DOI: http://dx.doi.org/10.1103/PhysRevLett.117.026401
We have uncovered a giant gyrotropic magneto-optical response for doped ferromagnetic manganite La2/3Ca1/3MnO3 around the near room-temperature paramagnetic-to-ferromagnetic transition. At odds with current wisdom, where this response is usually assumed to be fundamentally fixed by the electronic band structure, we point to the presence of small polarons as the driving force for this unexpected phenomenon.
We explain the observed properties by the intricate interplay of mobility, Jahn-Teller effect, and spin-orbit coupling of small polarons. As magnetic polarons are ubiquitously inherent to many strongly correlated systems, our results provide an original, general pathway towards the generation of magnetic-responsive gigantic gyrotropic responses that may open novel avenues for magnetoelectric coupling beyond the conventional modulation of magnetization.
Hits: 7643
Oxides for new-generation electronics
Giant Optical Polarization Rotation Induced by Spin-Orbit Coupling in Polarons
Also at ICMAB
-
Stabilization of the Ferroelectric Phase in Epitaxial Hf1–xZrxO2 Enabling Coexistence of Ferroelectric and Enhanced Piezoelectric Properties
- Information
- 18 June 2021 223 hit(s) Oxides
Systematic studies on polycrystalline Hf1–xZrxO2 films with varying Zr contents show that HfO2 films are paraelectric (monoclinic). If the Zr content is increased, films become ferroelectric (orthorhombic) and then antiferroelectric (tetragonal). HfO2 shows very good insulating properties and it is used in metal-oxide-semiconductor field-effect devices, while ZrO2 shows good piezoelectric properties, but it is antiferroelectric. In between, Hf0.5Zr0.5O2 shows good ferroelectric properties at the expense of poorer insulating and piezoelectric properties than HfO2 and ZrO2, respectively. -
Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices
- Information
- 25 May 2021 241 hit(s) Oxides
About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there is tremendous interest in this material and ferroelectric oxides are once again in the spotlight of the memories industry. Great efforts are being made to understand and control ferroelectric properties. Epitaxial films, which have fewer defects and a more controlled microstructure than polycrystalline films, can be very useful for this purpose. Epitaxial films of ferroelectric HfO2 have been much less investigated, but after the first report in 2015 significant progress has been achieved. -
Structure and phase transitions in A-site ordered RBaMn2O6(R=Pr,Nd) -perovskites with a polar ground state
- Information
- 14 May 2021 256 hit(s) Oxides
We report here a structural study of RBaMn2O6 (R=La, Pr, and Nd) compounds by means of synchrotron radiation x-ray powder diffraction and Raman spectroscopy. The three compounds are A-site ordered perovskites adopting the prototypical tetragonal structure at high temperature. A ferromagnetic transition is observed in the LaBaMn2O6 sample and the lattice parameters undergo anisotropic changes at TC related to the orientation of the magnetic moments. -
Tuning the tilting of the spiral plane by Mn doping in YBaCuFeO5 multiferroic
- Information
- 23 April 2021 328 hit(s) Oxides
The layered perovskite YBaCuFeO5 (YBCFO) is considered one of the best candidates to high-temperature chiral multiferroics with strong magnetoelectric coupling. In RBaCuFeO5 perovskites (R: rare-earth or Y) A-site cations are fully ordered whereas their magnetic properties strongly depend on the preparation process. They exhibit partial cationic disorder at the B-site that generates a magnetic spiral stabilized through directionally assisted long range coupling between canted locally frustrated spins. -
New Sensitive and Selective Chemical Sensors for Ni2+ and Cu2+ Ions: Insights into the Sensing Mechanism through DFT Methods
- Information
- 09 April 2021 368 hit(s) Oxides
We report the synthesis and theoretical study of two new colorimetric chemosensors with special selectivity and sensitivity to Ni2+ and Cu2+ ions over other metal cations in the CH3CN/H2O solution. Compounds (E)-4-((2-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (A) and (E)-4-((3-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (B) exhibited a drastic color change from yellow to colorless, which allows the detection of the mentioned metal cations through different techniques.
