Neutron-diffraction study of the magnetic structure of MnPt alloys

Severin, C. S.; Chen, C. W.; Stassis, C.

doi:10.1063/1.326458

Cited by 16 publications

(19 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The obtained values of lattice parameters and magnetic moments of MnPt and FePt magnetic ground states are in good agreement with the corresponding experimental data [8][9][10][11][22][23][24] and previous first-principles calculations. [25][26][27][28][29][30][31][32][33][34][35][36] Pt atoms are found to have either small ͑0.39 for MnPt, 0.34 for FePt for Model 3͒ or negligible magnetic moments ͑Models 1 and 2͒.…”

Section: Discussionsupporting

confidence: 88%

“…Such a small value for MnPt explains the experimentally observed controversy and sensitivity of the MCA to changes in composition and temperature. [8][9][10][11] Besides, being small, the out-of-plane MCA of MnPt is sensitive to the details of first-principles calculations. 26 The out-of-plane MCA of FePt is in good agreement with previous first-principles calculations.…”

Section: Discussionmentioning

confidence: 99%

“…[8][9][10][11][16][17][18] The small ͑ϳ7 meV͒ energetic preference of FM over AFM in FePt at T = 0 is in 25, it is shown that the correct FM ground state of FePt is predicted only when the generalized gradient approximation is used due to the more accurate estimation of lattice constants. The obtained values of lattice parameters and magnetic moments of MnPt Model 1͑AFM͒ and FePt Model 3͑FM͒ are in good agreement with the corresponding experimental data [8][9][10][11][22][23][24] and previous first-principles calculations. [25][26][27][28][29][30][31][32][33][34][35][36] Pt atoms are found to have either small or negligible magnetic moments.…”

Section: Ground Statesmentioning

confidence: 99%

“…1͒ with small tetragonal distortions. At room temperature, MnPt is found experimentally [8][9][10][11] to have antiferromagnetic order with aniferromagnetic coupling between adjacent Mn atoms in the ͑001͒ plane at distance a / ͱ 2 and ferromagnetic coupling between two adjacent Mn atoms in the ͓001͔ direction at distance c ͑see Model 1 in Fig. 1͒.…”

Section: Introductionmentioning

confidence: 95%

See 3 more Smart Citations

First-principles study of magnetic properties ofL10-ordered MnPt and FePt alloys

Chepulskii

Butler

2010

Phys. Rev. B

View full text Add to dashboard Cite

Using first-principles methods, we study the magnetic and electronic properties of three different spin configurations of the L1 0 phase of FePt and MnPt alloys. It is found that MnPt and FePt may be approximately considered as magnetic antipodes with opposite ferromagnetic ͑FM͒-antiferromagnetic ͑AFM͒ and in-plane/ out-of-plane magnetocrystalline anisotropy ͑MCA͒ relationships. In MnPt, the most stable phase is the AFM configuration with AFM chessboard spin coupling in the ͑001͒ plane, FM spin coupling between ͑001͒ planes, and all spin directions aligned in the ͑001͒ plane. Whereas in FePt, the most stable is the FM configuration with all spin directions aligned perpendicular to ͑001͒ plane. The out-of-plane MCA of MnPt is more than an order of magnitude less ͑ϳ0.1 meV͒ than that of FePt ͑ϳ2.9 meV͒ in their corresponding magnetic ground states. Our calculations indicate that an AFM state can be achieved in FePt by a small variation in tetragonality ratio ͑from 0.98 to 0.94͒. A pseudogap is observed at the Fermi energy for MnPt and just below the Fermi energy for FePt for the chessboard AFM model. This pseudogap may explain the ground-state magnetic configuration of MnPt.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: Ground Statesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

See 2 more Smart Citations

First-principles study of magnetic properties ofL10-ordered MnPt and FePt alloys

Chepulskii

Butler

2010

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…The lattice constants determined from the θ-2θ scan are a = b = 3.900 ± 0.004 Å and c = 3.644 ± 0.001 Å ( c/a = 0.934), which are similar to the XRD results shown above. For the single-crystal thin film, the integrated intensity can be expressed by <Ihkl>=A<q2>Fmag2sinfalse(2normalθfalse) ( 22 , 23 ), where A is a constant and Fmag2 is the magnetic structure factor. < q 2 > is the projection factor describing the component of magnetic moment perpendicular to the [ hkl ] direction.…”

Section: Resultsmentioning

confidence: 99%

Large spin-orbit torque efficiency enhanced by magnetic structure of collinear antiferromagnet IrMn

et al. 2019

View full text Add to dashboard Cite

Spin-orbit torque (SOT) offers promising approaches to developing energy-efficient memory devices by electric switching of magnetization. Compared to other SOT materials, metallic antiferromagnet (AFM) potentially allows the control of SOT through its magnetic structure. Here, combining the results from neutron diffraction and spin-torque ferromagnetic resonance experiments, we show that the magnetic structure of epitaxially grown L10-IrMn (a collinear AFM) is distinct from the widely presumed bulk one. It consists of twin domains, with the spin axes orienting toward [111] and [−111], respectively. This unconventional magnetic structure is responsible for much larger SOT efficiencies up to 0.60 ± 0.04, compared to 0.083 ± 0.002 for the polycrystalline IrMn. Furthermore, we reveal that this magnetic structure induces a large isotropic bulk contribution and a comparable anisotropic interfacial contribution to the SOT efficiency. Our findings shed light on the critical roles of bulk and interfacial antiferromagnetism to SOT generated by metallic AFM.

show abstract

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Alsaad

Obeidat

2020

Heliyon

View full text Add to dashboard Cite

We perform ab initio simulations to investigate the structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys. In particular, equilibrium structural lattice parameters, electronic properties such as density of states (DOS), partial density of states (PDOS) and electronic band structure of each binary alloys are investigated and interpreted. Moreover, the magneto-crystalline anisotropy energies (MAE) are calculated. We found MAE values of FePt, MnPt and CrPt 3 ordered alloys to be 2.66, 0.46 and 0.42 meV/f.u., respectively, corresponding to magneto-crystalline anisotropy constant K of 7.6 Â 10 7 , 1.3 Â 10 7 and 1.1 Â 10 7 erg/cm 3 , respectively. The large MAE and K values reveal that FePt, MnPt and CrPt 3 binary alloys are eligible to be key components in magneto-optical and opto-electronic devices. In addition, we estimated the Curie temperatures of the three ordered alloys from exchange energy. We found the T C of L1 0 -FePt, L1 0 -MnPt and L1 2 CrPt 3 to be 955 K, 989 K and 762 K, respectively. The high Curie temperatures obtained enable the ordered alloys to serve as write assist in Heat-Assisted Magnetic Recording (HAMR). We believe that our findings would pave the way to fabricate bulk and thin films based on the ordered binary FePt, MnPt, and CrPt 3 ordered alloys that have attractive electronic and magnetic properties.

show abstract

Neutron-diffraction study of the magnetic structure of MnPt alloys

Cited by 16 publications

References 14 publications

First-principles study of magnetic properties ofL10-ordered MnPt and FePt alloys

First-principles study of magnetic properties ofL10-ordered MnPt and FePt alloys

Large spin-orbit torque efficiency enhanced by magnetic structure of collinear antiferromagnet IrMn

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Contact Info

Product

Resources

About