Syntheses and magnetic properties of Rm+nCo5m+3nB2ncompounds

Chen, Yi; Liang, J. K.; Chen, X L; Liu, Quanlin; Shen, Baogen; Shen, Y P

doi:10.1088/0953-8984/11/42/306

Cited by 18 publications

(10 citation statements)

References 20 publications

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“…3 indicates that Nd 5 Co 21 B 4 is ferromagnetic with a Curie temperature of 570 K. Figure 4 shows the field dependence of magnetization of free powders at 5 K. According to the law of approach to saturation, the value of the saturation moment, M S ϭ31.1 B / f .u., was derived. 6,7,[12][13][14] It can be seen that both T C and Co decrease monotonously with increasing B content. 6,7,[12][13][14] It can be seen that both T C and Co decrease monotonously with increasing B content.…”

Section: Resultsmentioning

confidence: 99%

Crystal structure and magnetic properties of the compound Nd5Co21B4

Chu

Rao

Yang

et al. 2001

Journal of Applied Physics

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A compound Nd 5 Co 21 B 4 belonging to the series R mϩn Co 5mϩ3n B 2n with mϭ3, nϭ2 has been synthesized by melt spinning. The crystal structure and magnetic properties of the compound have been studied by means of x-ray diffraction and magnetic measurements. The compound crystallizes in a hexagonal structure with space group P6/mmm. The Curie temperature, the saturation moment, and the planar anisotropy field of the compound are 570 K, 31.1 B / f .u., and 861 kOe, respectively.

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Section: Resultsmentioning

confidence: 99%

Crystal structure and magnetic properties of the compound Nd5Co21B4

Chu

Rao

Yang

et al. 2001

Journal of Applied Physics

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“…The iterations were repeated until the energy eigenvalues of the consecutive iteration steps were the same within an error 0.01 mRy. The main contribution to DOS at the Fermi level (E F ) is provided by the Co atoms (see Table 1), especially d-type electrons localized close to the E F (above 90% contribution to the total DOS on the Co atoms).To estimate magnetic moments for inequivalent Co atoms Chen et al [9,10] realized similar discussion like Ogata et al [21] for Y 1+n Co 5+3n B 2n . The saturation magnetization µ s is equal to [9,10] [9,10].…”

Section: Methods Of Calculationsmentioning

confidence: 90%

“…The number of 4f electrons of Pr was fixed to two like for trivalent ion. The experimental values of the lattice constants [8][9][10] were used in the calculations. The self-consistent calculations were carried out for 259 k-points in the irreducible wedge of the Brillouin zone.…”

Section: Methods Of Calculationsmentioning

confidence: 99%

Ab‐initio electronic structure calculations for Pr₃Co₁₃B₂ and Pr₅Co₁₉B₆ compounds

Szajek

2006

Phys. Status Solidi (c)

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PACS 71.20. Be, 74.25.Ha Recently synthesized compounds Pr 3 Co 13 B 2 and Pr 5 Co 19 B 6 belong to the R m+n Co 5m+3n B 2n family with (m = 2, n = 1) and (m = 2, n = 3), respectively. They are studied because of their possible use as permanent magnets. The electronic structure is investigated by the tight binding version of the linear muffin-tin orbital method in the atomic sphere approximation (TB-LMTO ASA). The cobalt atoms occupying distinct sites have different types and number of neighbouring atoms and as a consequence the magnetic moments are different. The calculated values are compared with the results of bulk measurements.1 Introduction It has been known that boron substitution for the Co in RCo 5 Haucke compounds (R = rare earth element) leads to the formation of a series of systems expressed by the general formula R 1+n Co 5+3n B 2n.[1] (n = 0, 1, 2, ..., ∞). The unit cells have an interesting crystallographic regularity (see Fig. 1 in [2]), they are formed by alternate stacking of one layer of RCo 5 and n layers of RCo 3 B 2 . The partial substitution of the Co atoms by boron in the R 1+n Co 5+3n B 2n system causes a decrease of the Curie temperature (T C ), saturation magnetization (M S ) and effective intersublattice exchange interaction ([3] and ref. therein). Although the systems have uniaxial symmetry, their T C and M S are too low to be suitable for permanent magnet applications [4][5][6]. In order to overcome this drawback new series of compounds R m+1 Co 5m+3 B 2 with high Co content was proposed [7][8][9][10]. The mentioned above two homologous series can be expressed by a general formula R m+n Co 5m+3n B 2n , which is formed by alternate stacking of m parts of RCo 5 with n parts of RCo 3 B 2 along the c axis. The high values of the T C an M S are expected due to the high Co content. It has been shown by ab-initio calculations, e.g. [2,11,12], as well as by neutron diffraction measurements [13,14] that the magnetic moments of Co atoms depend on their local environment in R 1+n Co 5+3n B 2n . In this paper a study of the electronic structure of the Pr 3 Co 13 B 2 and Pr 5 Co 19 B 6 systems will be presented.

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“…In spite of earlier mistakes [24,25], it is now established that the compound orders ferromagnetically at T C = 720 K and undergoes a spin reorientation transition (SRT) at T SRT = 370 K [26,27] or 395 K [28]. The high temperature phase has been described as ferromagnetic, with the average Co moment m Co = 0.9μ B , as deduced from the low temperature magnetization at 5 K, after subtraction of the Nd sublattice magnetization deduced from Nd 3 Ni 13 B 2 [28].…”

Section: Nd 3 Co 13 Bmentioning

confidence: 99%