scholarly journals Nonequivalent Spin Exchanges of the Hexagonal Spin Lattice Affecting the Low-Temperature Magnetic Properties of RInO3(R = Gd, Tb, Dy): Importance of Spin–Orbit Coupling for Spin Exchanges between Rare-Earth Cations with Nonzero Orbital Moments

2018 ◽  
Vol 57 (15) ◽  
pp. 9260-9265 ◽  
Author(s):  
Elijah E. Gordon ◽  
Xiyue Cheng ◽  
Jaewook Kim ◽  
Sang-Wook Cheong ◽  
Shuiquan Deng ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Low Temperature ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Spin Lattice

scholarly journals Twisted magnetization phases in orbital-dominant rare-earth nitrides

2021 ◽  
Author(s):  
◽  
James McNulty
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Orbit Coupling ◽  
Ferromagnetic Semiconductors ◽  
Spin Moment ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Orbital Moment ◽  
Orbital Contribution ◽  
Rare Earth Nitrides

<p>In this thesis we investigate the magnetic properties of NdN and SmN, members of the rare-earth nitrides, a series of intrinsic ferromagnetic semiconductors. In rare-earth systems, the strong spin-orbit coupling of the partially filled 4ƒ shell ensures that there is a substantial orbital contribution to the ferromagnetic moment, in contrast to many transition metal systems where the orbital moment is usually quenched. In SmN and NdN the orbital moment actually exceeds the spin moment, and the resulting orbital dominant magnetization allows for the fabrication of a magnetic heterostructures showing novel behavior.  We report a new theoretical study of the magnetic properties on both SmN and NdN by considering the atomic-like 4ƒ electrons. These calculations incorporate spin-orbit coupling, the exchange interaction in a self-consistent mean-field approach, and crystal field interactions in an arbitrary-multiplet point-charge model. Our findings show excellent agreement with the experimentally measured ferromagnetic moments of SmN and NdN, representing an advance from previous theoretical studies.  We also report an experimental study on SmN/GdN heterostructures using the element-resolved method of x-ray magnetic circular dichroism (XMCD) to probe the magnetism. The competition between the orbital-dominant Zeeman coupling in SmN and the ferromagnetic spin-based interface exchange with GdN, which has purely a spin moment, results in a twisted magnetization profile. The depth profile of the magnetization derived from XMCD measurements showed good agreement with an analytical model developed to describe the competing interactions.  In a second study, a superlattice of NdN/GdN was investigated via XMCD and standard magnetometry techniques. A twisted magnetization was shown to be present due to the same mechanism as in the SmN/GdN system. By varying the maximum applied field and temperature, twisted phases were shown to develop in both GdN and NdN layers. These twisted phases in orbital-dominant ferromagnetic semiconductors represent a departure from previously explored spin-dominant metallic systems displaying similar twisted phases.</p>

scholarly journals Twisted magnetization phases in orbital-dominant rare-earth nitrides

2021 ◽  
Author(s):  
◽  
James McNulty
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Orbit Coupling ◽  
Ferromagnetic Semiconductors ◽  
Spin Moment ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Orbital Moment ◽  
Orbital Contribution ◽  
Rare Earth Nitrides

<p>In this thesis we investigate the magnetic properties of NdN and SmN, members of the rare-earth nitrides, a series of intrinsic ferromagnetic semiconductors. In rare-earth systems, the strong spin-orbit coupling of the partially filled 4ƒ shell ensures that there is a substantial orbital contribution to the ferromagnetic moment, in contrast to many transition metal systems where the orbital moment is usually quenched. In SmN and NdN the orbital moment actually exceeds the spin moment, and the resulting orbital dominant magnetization allows for the fabrication of a magnetic heterostructures showing novel behavior.  We report a new theoretical study of the magnetic properties on both SmN and NdN by considering the atomic-like 4ƒ electrons. These calculations incorporate spin-orbit coupling, the exchange interaction in a self-consistent mean-field approach, and crystal field interactions in an arbitrary-multiplet point-charge model. Our findings show excellent agreement with the experimentally measured ferromagnetic moments of SmN and NdN, representing an advance from previous theoretical studies.  We also report an experimental study on SmN/GdN heterostructures using the element-resolved method of x-ray magnetic circular dichroism (XMCD) to probe the magnetism. The competition between the orbital-dominant Zeeman coupling in SmN and the ferromagnetic spin-based interface exchange with GdN, which has purely a spin moment, results in a twisted magnetization profile. The depth profile of the magnetization derived from XMCD measurements showed good agreement with an analytical model developed to describe the competing interactions.  In a second study, a superlattice of NdN/GdN was investigated via XMCD and standard magnetometry techniques. A twisted magnetization was shown to be present due to the same mechanism as in the SmN/GdN system. By varying the maximum applied field and temperature, twisted phases were shown to develop in both GdN and NdN layers. These twisted phases in orbital-dominant ferromagnetic semiconductors represent a departure from previously explored spin-dominant metallic systems displaying similar twisted phases.</p>

scholarly journals The role of spin–orbit effects in the mobility of N+ ions moving in a helium gas at low temperature

2020 ◽  
Vol 74 (7) ◽  
Author(s):  
Lamia Aïssaoui ◽  
Peter J. Knowles ◽  
Moncef Bouledroua
Keyword(s):  
Low Temperature ◽  
Cross Sections ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Temperature Model ◽  
Helium Gas ◽  
Spin Orbit Interactions ◽  
High Level

Abstract The mobility of N+ ions in ground-state helium gas at very low temperature is examined with explicit inclusion of spin–orbit coupling effects. The ionic kinetics is treated theoretically with the three-temperature model. The N+–He interaction potentials, including spin–orbit coupling, are determined using high-level ab initio calculations. Then, the classical and quantal transport cross sections, both needed in the computation of the mobility coefficients, are calculated in terms of the collisional energy of the N+–He system. The numerical results, at temperature 4.3 K, show the spin–orbit interactions have negligible effect on the mobility coefficients. Graphical abstract

scholarly journals Giant Magnetoresistance Calculated from First Principles

1993 ◽  
Vol 313 ◽  
Author(s):  
W. H. Butler ◽  
James M. MacLaren ◽  
X.-G. Zhang
Keyword(s):  
Low Temperature ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Coherent Potential Approximation ◽  
Orbit Coupling ◽  
Approximation Technique ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Potential Approximation ◽  
Magnetoresis Tance

ABSTRACTThe Layer Korringa Kohn Rostoker-Coherent Potential Approximation technique was used to calculate the low temperature Giant Magnetoresistance from first principles for Co|Cu and permalloy|Cu superlattices. Our calculations predict large giant Magnetoresis-tance ratios for Co|Cu and extremely large ratios for permalloy|Cu for current perpendicular to the layers. Mechanisms such as spin-orbit coupling which mix spin channels are expected to greatly reduce the GMR effect for permalloy|Cu.

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