Papers by Suvankar Chakraverty
Journal of Materials Chemistry C, 2019
The physical properties of a nanoparticle change drastically when the particle size approaches th... more The physical properties of a nanoparticle change drastically when the particle size approaches the length scale of the relevant order parameter. Herein, we demonstrate the ferrimagnetic ground state of Cu 2 OSeO 3 nanoparticles, which is otherwise a chiral magnet (including large-size skyrmionic spin texture) in its bulk form. Theoretical studies suggest that such a pure ferrimagnetic ground state in this material (with low Dzyaloshinskii-Moriya interaction to Heisenberg interaction ratio) is possible only in the presence of magneto-crystalline anisotropy energy when the confinement size approaches the skyrmion size (B50 nm in bulk). These observations suggest the limit to realize an isolated single skyrmion.
Papers by Suvankar Chakraverty
Spontaneous atomic ordering and magnetism in epitaxially stabilized double perovskites
Spontaneous atomic ordering and magnetism in epitaxially stabilized double perovskites
ABSTRACT: We report epitaxial growth and structures of SrFeO 2.5 (SFO) films on SrTiO 3 (STO) (00... more ABSTRACT: We report epitaxial growth and structures of SrFeO 2.5 (SFO) films on SrTiO 3 (STO) (001) and (111) substrates by pulsed-laser deposition. Reflection high-energy electron diffraction intensity oscillations were observed during the initial growth on both substrates, reflecting a layer-by-layer growth mode of the formula unit cell. It was found that the films were stabilized with a monoclinic structure that was derived from the original orthorhombic structure of bulk Brownmillerite. Using an X-ray reciprocal space mapping technique, in-plane domain structures and the orientation relationship were investigated. In addition, the impact of laser spot area on the epitaxial structures was studied. For the films grown on the (001) STO, the orientation relationship was robust against the change of the laser spot area: SFO(001)//STO(001) and SFO(100)//STO(100) for the out-of-plane and the in-plane, respectively, with the [001] axis tilted toward the 4-fold a-andb-axes by ∼1.4°, wher...
ABSTRACT: We report epitaxial growth and structures of SrFeO 2.5 (SFO) films on SrTiO 3 (STO) (00... more ABSTRACT: We report epitaxial growth and structures of SrFeO 2.5 (SFO) films on SrTiO 3 (STO) (001) and (111) substrates by pulsed-laser deposition. Reflection high-energy electron diffraction intensity oscillations were observed during the initial growth on both substrates, reflecting a layer-by-layer growth mode of the formula unit cell. It was found that the films were stabilized with a monoclinic structure that was derived from the original orthorhombic structure of bulk Brownmillerite. Using an X-ray reciprocal space mapping technique, in-plane domain structures and the orientation relationship were investigated. In addition, the impact of laser spot area on the epitaxial structures was studied. For the films grown on the (001) STO, the orientation relationship was robust against the change of the laser spot area: SFO(001)//STO(001) and SFO(100)//STO(100) for the out-of-plane and the in-plane, respectively, with the [001] axis tilted toward the 4-fold a-andb-axes by ∼1.4°, wher...
Physical Review B
The carrier-density distribution near a conducting interface and the related band structure are t... more The carrier-density distribution near a conducting interface and the related band structure are topics of great contemporary importance in low-dimensional quantum solids. We propose a scheme, innovatively combining the spectroscopy techniques of photoluminescence and time-correlated single-photon counting with transport measurements of resistivity to unravel the carrier distribution, the shape of quantum well, energy subbands, and Fermi surfaces of the conducting interface of LaVO 3 and SrTiO 3. Electronic parameters, such as the carrier density, the mobility, estimated from the electrical measurements, are in remarkably good agreement with those extracted from the spectroscopy with theoretical modeling providing a bridge between the two sets of data analysis.
Physical Review B
The carrier-density distribution near a conducting interface and the related band structure are t... more The carrier-density distribution near a conducting interface and the related band structure are topics of great contemporary importance in low-dimensional quantum solids. We propose a scheme, innovatively combining the spectroscopy techniques of photoluminescence and time-correlated single-photon counting with transport measurements of resistivity to unravel the carrier distribution, the shape of quantum well, energy subbands, and Fermi surfaces of the conducting interface of LaVO 3 and SrTiO 3. Electronic parameters, such as the carrier density, the mobility, estimated from the electrical measurements, are in remarkably good agreement with those extracted from the spectroscopy with theoretical modeling providing a bridge between the two sets of data analysis.
RSC Advances
Magnetic hyperthermia-based cancer therapy mediated by magnetic nanomaterials is a promising anti... more Magnetic hyperthermia-based cancer therapy mediated by magnetic nanomaterials is a promising antitumoral nanotherapy, owning to its power to generate heat under the application of an alternating magnetic field.
RSC Advances
Magnetic hyperthermia-based cancer therapy mediated by magnetic nanomaterials is a promising anti... more Magnetic hyperthermia-based cancer therapy mediated by magnetic nanomaterials is a promising antitumoral nanotherapy, owning to its power to generate heat under the application of an alternating magnetic field.
arXiv: Materials Science, 2011
We report on atomic ordering of B-site transition-metals and magnetic properties of epitaxial La2... more We report on atomic ordering of B-site transition-metals and magnetic properties of epitaxial La2CrFeO6 double-perovskite films grown by pulsed-laser deposition under various conditions. The highest ordered sample exhibited a fraction of antisite-disorder of only 0.05 and a saturation magnetization of ~2\mu_{B} per formula unit at 5 K. The result is consistent with the antiferromagnetic ordering of local spin moment (3d^{3}_{\downarrow}3d^{5}_{\uparrow}; S = -3/2+5/2 = 1). Therefore, the magnetic ground state of La2CrFeO6 double-perovskite that has been long debate is unambiguously revealed to be ferrimagnetic. Our results present a wide opportunity to explore novel magnetic properties of binary transition-metal perovskites upon epitaxial stabilization of the ordered phase.
arXiv: Materials Science, 2011
We report on atomic ordering of B-site transition-metals and magnetic properties of epitaxial La2... more We report on atomic ordering of B-site transition-metals and magnetic properties of epitaxial La2CrFeO6 double-perovskite films grown by pulsed-laser deposition under various conditions. The highest ordered sample exhibited a fraction of antisite-disorder of only 0.05 and a saturation magnetization of ~2\mu_{B} per formula unit at 5 K. The result is consistent with the antiferromagnetic ordering of local spin moment (3d^{3}_{\downarrow}3d^{5}_{\uparrow}; S = -3/2+5/2 = 1). Therefore, the magnetic ground state of La2CrFeO6 double-perovskite that has been long debate is unambiguously revealed to be ferrimagnetic. Our results present a wide opportunity to explore novel magnetic properties of binary transition-metal perovskites upon epitaxial stabilization of the ordered phase.
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Papers by Suvankar Chakraverty
Papers by Suvankar Chakraverty