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Exchange Interactions and Curie Temperature of Ce-Substituted SmCo_{5}

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## Abstract

**:**

## 1. Introduction

## 2. Results and Discussion

#### 2.1. Crystal Structure

#### 2.2. Exchange Interactions

#### 2.3. Calculations of Curie Temperature

## 3. Conclusions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Buschow, K. Intermetallic compounds of rare-earth and 3d transition metals. Rep. Prog. Phys.
**1977**, 40, 1179. [Google Scholar] [CrossRef] - Strnat, K.; Hoffer, G.; Olson, J.; Ostertag, W. A Family of New Cobalt-base Permanent Magnet Materials. J. Appl. Phys.
**1967**, 38, 1001. [Google Scholar] [CrossRef] - Fingers, R.T.; Rubertus, C.S. Application of high temperature magnetic materials. IEEE Trans. Magn.
**2000**, 36, 3373–3375. [Google Scholar] [CrossRef] - Liu, J.F.; Zhang, Y.; Dimitrov, D.; Hadjipanayis, G.C. Microstructure and high temperature magnetic properties of Sm (Co, Cu, Fe, Zr)
_{z}(z = 6.7–9.1) permanent magnets. J. Appl. Phys.**1999**, 85, 2800–2804. [Google Scholar] [CrossRef] - Lv, L.; Wang, F.Q.; Zheng, Q.; Du, J.; Dong, X.L.; Cui, P.; Liu, J.P. Preparation and Magnetic Properties of Anisotropic SmCo
_{5}/Co Composite Particles. Acta Metall. Sin. (Engl. Lett.)**2017**, 31, 143–147. [Google Scholar] [CrossRef] - Ji, W.; Fu, C.B.; Gao, H. Searching for new spin-dependent interactions with SmCo
_{5}spin sources and a spin-exchange-relaxation-free comagnetometer. Phys. Rev. D**2017**, 95, 075014. [Google Scholar] [CrossRef] - Suzuki, A.; Hotta, Y.; Yamada, M.; Ohtake, M.; Futamoto, M.; Kirino, F.; Inaba, N. Structure and magnetic properties of SmCo
_{5}/X (X = Fe, Fe-Co, Co) magnetic bilayer films on MgO (110) substrate. J. Magn. Magn. Mater.**2017**, 440, 74–78. [Google Scholar] [CrossRef] - Buschow, K.H.J.; Van Diepen, A.M.; De Wijn, H.W. Crystal-field anisotropy of Sm3+ in SmCo
_{5}. Solid State Commun.**1974**, 15, 903–906. [Google Scholar] [CrossRef] - Sabiryanov, R.F.; Jaswal, S.S. Magnetic properties of hard/soft composites: SmCo
_{5}/Co_{1−x}Fe_{x}. Phys. Rev. B**1998**, 58, 12071. [Google Scholar] [CrossRef] - Larson, P.; Mazin, I.; Papaconstantopoulos, D.A. Calculation of magnetic anisotropy energy in SmCo
_{5}. Phys. Rev. B**2003**, 67, 214405. [Google Scholar] [CrossRef] - Richter, M.; Oppeneer, P.M.; Eschrig, H.; Johansson, B. Calculated crystal-field parameters of SmCo
_{5}. Phys. Rev. B**1992**, 42, 13919. [Google Scholar] [CrossRef] - Sayama, J.; Asahi, T.; Mizutani, K.; Osaka, T. Newly developed SmCo
_{5}thin film with perpendicular magnetic anisotropy. J. Phys. D Appl. Phys.**2003**, 37, L1. [Google Scholar] [CrossRef] - Sayama, J.; Mizutani, K.; Asahi, T.; Osaka, T. Thin films of SmCo
_{5}with very high perpendicular magnetic anisotropy. Appl. Phys. Lett.**2004**, 85, 5640–5642. [Google Scholar] [CrossRef] - Rong, C.; Poudyal, N.; Liu, X.B.; Zhang, Y.; Kramer, M.J.; Ping Liu, J. High temperature magnetic properties of SmCo
_{5}/α-Fe (Co) bulk nanocomposite magnets. Appl. Phys. Lett.**2012**, 101, 152401. [Google Scholar] [CrossRef] - Hao, S.Q.; Chen, N.X.; Shen, J. Atomistic study of rare-earth compounds R
_{2}Fe_{1}7 (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu) and Nd_{2}Fe_{1}7N_{x}. Model. Simul. Mater. Sci. Eng.**2002**, 10, 425. [Google Scholar] [CrossRef] - Kneller, E.F.; Hawig, R. The exchange-spring magnet: A new material principle for permanent magnets. IEEE Trans. Magn.
**1991**, 27, 3560–3588. [Google Scholar] [CrossRef] - Al-Omari, I.A.; Sellmyer, D.J. Magnetic properties of nanostructured CoSm/FeCo films. Phys. Rev. B
**1995**, 52, 3441. [Google Scholar] [CrossRef] - Jiang, J.S.; Pearson, E.; Liu, Z.Y.; Kabius, B.; Trasobares, S.; Miller, D.J.; Bader, S.D. A new approach for improving exchange-spring magnets. J. Appl. Phys.
**2005**, 97, 10K311. [Google Scholar] [CrossRef] - Cheng, W.; Dai, Y.; Hu, H.; Cheng, X.; Miao, X. Effect of Cu Substitution on the Magnetic Properties of SmCo
_{5}Film with Perpendicular Magnetic Anisotropy. J. Electron. Mater.**2012**, 41, 2178–2183. [Google Scholar] [CrossRef] - Liu, X.B.; Altounian, Z. The mixing of Fe/Co and its effect on the exchange interaction in SmCo
_{5}/α-Fe nanocomposites: A first-principles study. J. Appl. Phys.**2012**, 111, 07B526. [Google Scholar] [CrossRef] - Fukuzaki, T.; Iwane, H.; Abe, K.; Doi, T.; Tamura, R.; Oikawa, T. Effect of Zr, V, Nb, Mo, and Ta substitutions on magnetic properties and microstructure of melt-spun SmCo
_{5}magnets. J. Appl. Phys.**2014**, 115, 17A760. [Google Scholar] [CrossRef] - Söderlind, P.; Landa, A.; Locht, I.L.M.; Åberg, D.; Kvashnin, Y.; Pereiro, M.; Däne, M.; Turchi, P.E.A.; Antropov, V.P.; Eriksson, O. Prediction of the new efficient permanent magnet SmCoNiFe
_{3}. Phys. Rev. B**2017**, 96, 100404(R). [Google Scholar] [CrossRef] - Sagawa, M.; Fujimura, S.; Yamamoto, H.; Matsuura, Y.; Hiraga, K. Permanent magnet materials based on the rare earth-iron-boron tetragonal compounds. IEEE Trans. Magn.
**1984**, 20, 1584–1589. [Google Scholar] [CrossRef] [Green Version] - Vial, F.; Joly, F.; Nevalainen, E.; Sagawa, M.; Hiraga, K.; Park, K.T. Improvement of coercivity of sintered NdFeB permanent magnets by heat treatment. J. Magn. Magn. Mater.
**2002**, 242, 1329–1334. [Google Scholar] [CrossRef] - Zhang, J.J.; Gao, H.M.; Yan, Y.; Bai, X.; Su, F.; Wang, W.Q.; Du, X.B. Morphology and magnetic properties of CeCo
_{5}submicron flakes prepared by surfactant-assisted high-energy ball milling. J. Magn. Magn. Mater.**2012**, 324, 3272–3275. [Google Scholar] [CrossRef] - Narita, K.; Yamamoto, H. Crystal structure and magnetic properties in CeCo
_{5}-PrCo_{5}alloy system. IEEE Trans. Mag.**1981**, 17, 2466–2470. [Google Scholar] [CrossRef] - Nagel, H. Hard magnetic materials: Rare earth-transition metal and Fe-Nd-B. In Powder Metallurgy Data; Landolt-Börnstein—Group VIII Advanced Materials and Technologies; Springer: New York, NY, USA, 2003; Volume 2A1. [Google Scholar]
- Jekal, S.; Loeffler, J.; Charilaou, M. Pushing the limits of magnetic anisotropy in the Sm-Co system. arXiv, 2018; arXiv:1807.09257. [Google Scholar]
- Charilaou, M.; Hagmann, A.; Jekal, S.; Koch, L.; Telford, S.; Stoica, M.; Schaublin, R.; Simon, R.; Löffler, J. Enhanced magnetocrystalline anisotropy in melt-spun Ce-substituted SmCo5 magnets. Unpublished work.
- Zhang, Z.D.; Liu, W.; Liu, J.P.; Sellmyer, D.J. Metastable phases in rare-earth permanent-magnet materials. J. Phys. D Appl. Phys.
**2000**, 33, R217. [Google Scholar] [CrossRef] - Nordström, L.; Eriksson, O.; Brooks, M.; Johansson, B. Theory of ferromagnetism in CeCo
_{5}. Phys. Rev. B**1990**, 41, 9111. [Google Scholar] [CrossRef] - Gignoux, D.; Givord, F.; Lemaire, R.; Launois, H.; Sayetat, F. Valence state of cerium in the hexagonal CeM
_{5}compounds with the transition metals. J. Phys.**1982**, 43, 173–180. [Google Scholar] [CrossRef] - Givord, D.; Laforest, J.; Lemaire, R.; Lu, Q. Cobalt magnetism in RCo
_{5}-Intermetallics: Onset of 3d magnetism and magnetocrystalline anisotropy (R = Rare earth or Th). J. Magn. Magn. Mater.**1983**, 31, 191–196. [Google Scholar] [CrossRef] - Kashyap, A.; Skomski, R.; Sabiryanov, R.F.; Jaswal, S.S.; Sellmyer, D.J. Exchange interactions and Curie temperature of Y-Co compounds. IEEE Trans. Magn.
**2003**, 39, 2908–2910. [Google Scholar] [CrossRef] - Denton, A.R.; Ashcroft, N.W. Vegard’s law. Phys. Rev. A
**1991**, 43, 3161. [Google Scholar] [CrossRef] - Van Schilfgaarde, M.; Antropov, V. First-principles exchange interactions in Fe, Ni, and Co. J. Appl. Phys.
**1999**, 85, 4827–4829. [Google Scholar] [CrossRef] - Stewart, M.; Yee, C.H.; Liu, J.; Kareev, M.; Smith, R.; Chapler, B.; Varela, M.; Ryan, P.; Haule, K.; Chakhalian, J.; et al. Optical study of strained ultrathin films of strongly correlated LaNiO
_{3}. Phys. Rev. B**2011**, 83, 075125. [Google Scholar] [CrossRef] - Yim, C.M.; Trainer, C.; Aluru, R.; Chi, S.; Hardy, W.N.; Liang, R.; Bonn, D.; Wahl, P. Discovery of a strain-stabilised smectic electronic order in LiFeAs. Nat. Commun.
**2018**, 9, 2602. [Google Scholar] [CrossRef] - Agrestini, S.; Saini, N.; Bianconi, G.; Bianconi, A. The strain of CuO
_{2}lattice: The second variable for the phase diagram of cuprate perovskites. J. Phys. A Math. Gen.**2003**, 36, 9133. [Google Scholar] [CrossRef] - Gao, S.; Flicker, F.; Sankar, R.; Zhao, H.; Ren, Z.; Rachmilowitz, B.; Balachandar, S.; Chou, F.; Burch, K.S.; Wang, Z.; et al. Atomic-scale strain manipulation of a charge density wave. Proc. Natl. Acad. Sci. USA
**2018**, 115, 6986–6990. [Google Scholar] [CrossRef]

**Figure 1.**Illustration of the crystal structure of Sm${}_{1-x}$Ce${}_{x}$Co${}_{5}$ for x = 0, 0.125, 0.25, 0.375, 0.5, 0.75, and 1. Gray, red, and blue spheres correspond to Sm, Ce, and Co atoms, respectively.

**Figure 2.**Modification of the effective strain (square) compared to the SmCo${}_{5}$ cell, and the atomic volume (circle) in Sm${}_{1-x}$Ce${}_{x}$Co${}_{5}$, as a function of Ce substitution x.

**Figure 3.**Intrinsic magnetic properties as a function of strain in SmCo${}_{5}$: (

**a**) atomic magnetic moments of Co atoms at sites 2c (triangles) and 3g (inverse-triangles) and Sm atoms (circles); (

**b**) exchange coupling between Co sites i and j; and (

**c**) effective total ferromagnetic exchange energy.

**Figure 4.**Magnetic properties as a function of Ce-substitution of Sm: (

**a**) atomic magnetic moments of Co atoms at sites 2c (triangles) and 3g (inverse-triangles) and Sm atoms (circles); (

**b**) exchange coupling between Co sites i and j; and (

**c**) effective total ferromagnetic exchange energy.

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**MDPI and ACS Style**

Jekal, S.
Exchange Interactions and Curie Temperature of Ce-Substituted SmCo_{5}. *Condens. Matter* **2019**, *4*, 11.
https://doi.org/10.3390/condmat4010011

**AMA Style**

Jekal S.
Exchange Interactions and Curie Temperature of Ce-Substituted SmCo_{5}. *Condensed Matter*. 2019; 4(1):11.
https://doi.org/10.3390/condmat4010011

**Chicago/Turabian Style**

Jekal, Soyoung.
2019. "Exchange Interactions and Curie Temperature of Ce-Substituted SmCo_{5}" *Condensed Matter* 4, no. 1: 11.
https://doi.org/10.3390/condmat4010011