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E. V. Sampathkumaran - One of the best experts on this subject based on the ideXlab platform.
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Existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system Tb 2 BaNiO 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to $3d$ and $4f$ electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on ${\mathrm{Tb}}_{2}{\mathrm{BaNiO}}_{5}$ (orthorhombic, $Immm$ centrosymmetric space group), exhibiting N\'eel order below $({T}_{N}=)\phantom{\rule{0.28em}{0ex}}63\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below ${T}_{N}$, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations ($\mathrm{GGA}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathrm{SO}$ and $\mathrm{GGA}+\mathrm{U}+\mathrm{SO}$ approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Canting Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bond Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism---that is, a critical Canting Angle coupled with exchange striction---to induce multiferroicity in magnetic insulators with canted spins.
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existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the haldane spin chain system tb 2 banio 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to 3d and 4f electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on Tb2BaNiO5 (orthorhombic, Immm centrosymmetric space group), exhibiting Neel order below (TN) 63 K, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below TN, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations (GCA plus SO and GCA plus U plus SO approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Cantingle Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bong Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism, that is, a critical Canting Angle coupled with exchangestriction, to induce multiferroicity in magnetic insulators with canted spins.
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Origin of destruction of multiferroicity in Tb2BaNiO5 by Sr doping and its implications
Journal of Alloys and Compounds, 1Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, Kartik K. Iyer, Sanjay Kumar Upadhyay, Andreas Hoser, Kalobaran Maiti, E. V. SampathkumaranAbstract:Abstract The orthorhombic Haldane-spin chain compound Tb2BaNiO5 (Neel order, TN1= 63 K) has been shown to be an exotic multiferroic system below (TN2=) 25 K due to various fascinating features, pointing to a strong potential for the advancement of concepts in this field. In particular, the rare-earth ions play a direct decisive role unlike in many other well-known multiferroic materials and there appears to be a critical Canting Angle, developing below TN2, subtended by Tb 4 f and Ni 3d moments to trigger this cross-coupling phenomenon. However, for a small replacement of Sr for Ba, viz. in Tb2Ba0.9Sr0.1NiO5, ferroelectricity was reported to get destroyed, but retaining magnetic features at (TN1=) 55 K and (TN2 =) 14 K. In this article, we address the origin of suppression of multiferrocity in this Sr-doped system through neutron diffraction studies and density functional theory calculations. We find that, unlike in Tb2BaNiO5, there is no pronounced change in the relative Canting Angle of the magnetic moments around TN2 and that the absolute value of this parameter down to 2 K fails to exceed the critical value noted for the parent, thereby explaining the origin of destruction of magnetoelectric coupling in the Sr-doped material. This finding renders strong support to the proposal of possible existence of ‘critical Canting Angle’ – at least in some cases – to induce multiferroicity, apart from serving as a route to engineer multiferroic materials for applications.
Ram Kumar - One of the best experts on this subject based on the ideXlab platform.
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Existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system Tb 2 BaNiO 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to $3d$ and $4f$ electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on ${\mathrm{Tb}}_{2}{\mathrm{BaNiO}}_{5}$ (orthorhombic, $Immm$ centrosymmetric space group), exhibiting N\'eel order below $({T}_{N}=)\phantom{\rule{0.28em}{0ex}}63\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below ${T}_{N}$, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations ($\mathrm{GGA}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathrm{SO}$ and $\mathrm{GGA}+\mathrm{U}+\mathrm{SO}$ approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Canting Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bond Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism---that is, a critical Canting Angle coupled with exchange striction---to induce multiferroicity in magnetic insulators with canted spins.
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existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the haldane spin chain system tb 2 banio 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to 3d and 4f electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on Tb2BaNiO5 (orthorhombic, Immm centrosymmetric space group), exhibiting Neel order below (TN) 63 K, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below TN, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations (GCA plus SO and GCA plus U plus SO approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Cantingle Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bong Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism, that is, a critical Canting Angle coupled with exchangestriction, to induce multiferroicity in magnetic insulators with canted spins.
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Origin of destruction of multiferroicity in Tb2BaNiO5 by Sr doping and its implications
Journal of Alloys and Compounds, 1Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, Kartik K. Iyer, Sanjay Kumar Upadhyay, Andreas Hoser, Kalobaran Maiti, E. V. SampathkumaranAbstract:Abstract The orthorhombic Haldane-spin chain compound Tb2BaNiO5 (Neel order, TN1= 63 K) has been shown to be an exotic multiferroic system below (TN2=) 25 K due to various fascinating features, pointing to a strong potential for the advancement of concepts in this field. In particular, the rare-earth ions play a direct decisive role unlike in many other well-known multiferroic materials and there appears to be a critical Canting Angle, developing below TN2, subtended by Tb 4 f and Ni 3d moments to trigger this cross-coupling phenomenon. However, for a small replacement of Sr for Ba, viz. in Tb2Ba0.9Sr0.1NiO5, ferroelectricity was reported to get destroyed, but retaining magnetic features at (TN1=) 55 K and (TN2 =) 14 K. In this article, we address the origin of suppression of multiferrocity in this Sr-doped system through neutron diffraction studies and density functional theory calculations. We find that, unlike in Tb2BaNiO5, there is no pronounced change in the relative Canting Angle of the magnetic moments around TN2 and that the absolute value of this parameter down to 2 K fails to exceed the critical value noted for the parent, thereby explaining the origin of destruction of magnetoelectric coupling in the Sr-doped material. This finding renders strong support to the proposal of possible existence of ‘critical Canting Angle’ – at least in some cases – to induce multiferroicity, apart from serving as a route to engineer multiferroic materials for applications.
D. T. Adroja - One of the best experts on this subject based on the ideXlab platform.
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Existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system Tb 2 BaNiO 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to $3d$ and $4f$ electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on ${\mathrm{Tb}}_{2}{\mathrm{BaNiO}}_{5}$ (orthorhombic, $Immm$ centrosymmetric space group), exhibiting N\'eel order below $({T}_{N}=)\phantom{\rule{0.28em}{0ex}}63\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below ${T}_{N}$, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations ($\mathrm{GGA}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathrm{SO}$ and $\mathrm{GGA}+\mathrm{U}+\mathrm{SO}$ approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Canting Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bond Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism---that is, a critical Canting Angle coupled with exchange striction---to induce multiferroicity in magnetic insulators with canted spins.
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existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the haldane spin chain system tb 2 banio 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to 3d and 4f electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on Tb2BaNiO5 (orthorhombic, Immm centrosymmetric space group), exhibiting Neel order below (TN) 63 K, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below TN, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations (GCA plus SO and GCA plus U plus SO approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Cantingle Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bong Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism, that is, a critical Canting Angle coupled with exchangestriction, to induce multiferroicity in magnetic insulators with canted spins.
Sanjay Kumar Upadhyay - One of the best experts on this subject based on the ideXlab platform.
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Existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system Tb 2 BaNiO 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to $3d$ and $4f$ electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on ${\mathrm{Tb}}_{2}{\mathrm{BaNiO}}_{5}$ (orthorhombic, $Immm$ centrosymmetric space group), exhibiting N\'eel order below $({T}_{N}=)\phantom{\rule{0.28em}{0ex}}63\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below ${T}_{N}$, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations ($\mathrm{GGA}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathrm{SO}$ and $\mathrm{GGA}+\mathrm{U}+\mathrm{SO}$ approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Canting Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bond Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism---that is, a critical Canting Angle coupled with exchange striction---to induce multiferroicity in magnetic insulators with canted spins.
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existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the haldane spin chain system tb 2 banio 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to 3d and 4f electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on Tb2BaNiO5 (orthorhombic, Immm centrosymmetric space group), exhibiting Neel order below (TN) 63 K, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below TN, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations (GCA plus SO and GCA plus U plus SO approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Cantingle Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bong Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism, that is, a critical Canting Angle coupled with exchangestriction, to induce multiferroicity in magnetic insulators with canted spins.
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Origin of destruction of multiferroicity in Tb2BaNiO5 by Sr doping and its implications
Journal of Alloys and Compounds, 1Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, Kartik K. Iyer, Sanjay Kumar Upadhyay, Andreas Hoser, Kalobaran Maiti, E. V. SampathkumaranAbstract:Abstract The orthorhombic Haldane-spin chain compound Tb2BaNiO5 (Neel order, TN1= 63 K) has been shown to be an exotic multiferroic system below (TN2=) 25 K due to various fascinating features, pointing to a strong potential for the advancement of concepts in this field. In particular, the rare-earth ions play a direct decisive role unlike in many other well-known multiferroic materials and there appears to be a critical Canting Angle, developing below TN2, subtended by Tb 4 f and Ni 3d moments to trigger this cross-coupling phenomenon. However, for a small replacement of Sr for Ba, viz. in Tb2Ba0.9Sr0.1NiO5, ferroelectricity was reported to get destroyed, but retaining magnetic features at (TN1=) 55 K and (TN2 =) 14 K. In this article, we address the origin of suppression of multiferrocity in this Sr-doped system through neutron diffraction studies and density functional theory calculations. We find that, unlike in Tb2BaNiO5, there is no pronounced change in the relative Canting Angle of the magnetic moments around TN2 and that the absolute value of this parameter down to 2 K fails to exceed the critical value noted for the parent, thereby explaining the origin of destruction of magnetoelectric coupling in the Sr-doped material. This finding renders strong support to the proposal of possible existence of ‘critical Canting Angle’ – at least in some cases – to induce multiferroicity, apart from serving as a route to engineer multiferroic materials for applications.
Tulika Maitra - One of the best experts on this subject based on the ideXlab platform.
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Existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the Haldane spin-chain system Tb 2 BaNiO 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to $3d$ and $4f$ electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on ${\mathrm{Tb}}_{2}{\mathrm{BaNiO}}_{5}$ (orthorhombic, $Immm$ centrosymmetric space group), exhibiting N\'eel order below $({T}_{N}=)\phantom{\rule{0.28em}{0ex}}63\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below ${T}_{N}$, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations ($\mathrm{GGA}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}\mathrm{SO}$ and $\mathrm{GGA}+\mathrm{U}+\mathrm{SO}$ approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Canting Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bond Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism---that is, a critical Canting Angle coupled with exchange striction---to induce multiferroicity in magnetic insulators with canted spins.
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existence of a critical Canting Angle of magnetic moments to induce multiferroicity in the haldane spin chain system tb 2 banio 5
Physical Review B, 2019Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, D. T. Adroja, Kartik K. Iyer, Sanjay Kumar Upadhyay, E. V. SampathkumaranAbstract:We report an unusual canted magnetism due to 3d and 4f electrons, occupying two different crystallographic sites, with its consequence to electric dipole order. This is based on neutron powder diffraction measurements on Tb2BaNiO5 (orthorhombic, Immm centrosymmetric space group), exhibiting Neel order below (TN) 63 K, to understand multiferroic behavior below 25 K. The magnetic structure is made up of Ni and Tb magnetic moments, which are found to be mutually canted in the entire temperature range below TN, though collinearity is seen within each sublattice, as known in the past. First-principles density functional theory calculations (GCA plus SO and GCA plus U plus SO approximations) support such a canted ground state. The intriguing finding, being reported here, is that there is a sudden increase in this Tb-Ni relative Cantingle Angle at the temperature (that is, at 25 K) at which spontaneous electric polarization sets in, with bond distance and bong Angle anomalies. This finding emphasizes the need for a new spin-driven polarization mechanism, that is, a critical Canting Angle coupled with exchangestriction, to induce multiferroicity in magnetic insulators with canted spins.
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Origin of destruction of multiferroicity in Tb2BaNiO5 by Sr doping and its implications
Journal of Alloys and Compounds, 1Co-Authors: Ram Kumar, Sudhindra Rayaprol, Sarita Rajput, Tulika Maitra, Kartik K. Iyer, Sanjay Kumar Upadhyay, Andreas Hoser, Kalobaran Maiti, E. V. SampathkumaranAbstract:Abstract The orthorhombic Haldane-spin chain compound Tb2BaNiO5 (Neel order, TN1= 63 K) has been shown to be an exotic multiferroic system below (TN2=) 25 K due to various fascinating features, pointing to a strong potential for the advancement of concepts in this field. In particular, the rare-earth ions play a direct decisive role unlike in many other well-known multiferroic materials and there appears to be a critical Canting Angle, developing below TN2, subtended by Tb 4 f and Ni 3d moments to trigger this cross-coupling phenomenon. However, for a small replacement of Sr for Ba, viz. in Tb2Ba0.9Sr0.1NiO5, ferroelectricity was reported to get destroyed, but retaining magnetic features at (TN1=) 55 K and (TN2 =) 14 K. In this article, we address the origin of suppression of multiferrocity in this Sr-doped system through neutron diffraction studies and density functional theory calculations. We find that, unlike in Tb2BaNiO5, there is no pronounced change in the relative Canting Angle of the magnetic moments around TN2 and that the absolute value of this parameter down to 2 K fails to exceed the critical value noted for the parent, thereby explaining the origin of destruction of magnetoelectric coupling in the Sr-doped material. This finding renders strong support to the proposal of possible existence of ‘critical Canting Angle’ – at least in some cases – to induce multiferroicity, apart from serving as a route to engineer multiferroic materials for applications.