B48B2C2 und B48B2N2, zwei Nichtmetallboride mit der Struktur des sog. I tetragonalen Bors

Ploog, K.; Schmidt, H.; Amberger, E.; Will, G.; Kossobutzki, K.H.

doi:10.1016/0022-5088(72)90187-7

Cited by 76 publications

(43 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We note that the representation of the atomic configuration of t-B 50 N 2 has still not been decisive due to a variety of ways for individual boron and nitrogen atoms to fully and/or partially occupy 13 14 15 16 at.% N different interstitial sites [70][71][72]. In the present work, the atomic configuration of t-B 50 N 2 , recently proposed by Uemura et al [72] is chosen, as it is found to be the lowest-energy configuration, among several considered possible occupations of the interstitial atoms.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamic stability and properties of boron subnitrides from first principles

2017

View full text Add to dashboard Cite

We use the first-principles approach to clarify the thermodynamic stability as a function of pressure and temperature of three different α-rhombohedral-boron-like boron subnitrides, with the compositions of B 6 N, B 13 N 2 , and B 38 N 6 , proposed in the literature. We find that, out of these subnitrides with the structural units of B 12 (N-N), B 12 (NBN), and [B 12 (N − N)] 0.33 [B 12 (NBN)] 0.67 , respectively, only B 38 N 6 , represented by [B 12 (N − N)] 0.33 [B 12 (NBN)] 0.67 , is thermodynamically stable. Beyond a pressure of about 7.5 GPa depending on the temperature, also B 38 N 6 becomes unstable, and decomposes into cubic boron nitride and α-tetragonalboron-like boron subnitride B 50 N 2 . The thermodynamic stability of boron subnitrides and relevant competing phases is determined by the Gibbs free energy, in which the contributions from the lattice vibrations and the configurational disorder are obtained within the quasiharmonic and the mean-field approximations, respectively. We calculate lattice parameters, elastic constants, phonon and electronic density of states, and demonstrate that [B 12 (N − N)] 0.33 [B 12 (NBN)] 0.67 is both mechanically and dynamically stable, and is an electrical semiconductor. The simulated x-ray powder-diffraction pattern as well as the calculated lattice parameters of [B 12 (N − N)] 0.33 [B 12 (NBN)] 0.67 are found to be in good agreement with those of the experimentally synthesized boron subnitrides reported in the literature, verifying that B 38 N 6 is the stable composition of α-rhombohedral-boron-like boron subnitride.

show abstract

Section: Resultsmentioning

confidence: 99%

Thermodynamic stability and properties of boron subnitrides from first principles

2017

View full text Add to dashboard Cite

show abstract

“…Considerably less research has been carried out on the synthesis and properties of nonstoichiometric B 1-x N x boron nitrides. Mainly, boron subnitrides (x<0.5) resembling the α-rhombohedral (rh) boron structure have attracted some interest in the last decades [12][13][14][15][16][17][18][19][20][21], inspired by the technological interest of boron-rich hard refractory compounds (B 4 C, B 6 O,…) [22].…”

mentioning

confidence: 99%

“…On the one hand, high temperature (>1000ºC) chemical vapor deposition (CVD) techniques have been used for the deposition of boron subnitride layers. For instance, coatings with B 58 N to B 23 N compositions and Itetragonal structure were obtained through pyrolysis of BBr 3 -H 2 -N 2 [14,19]. Moreover, Saitoh et al proposed the presence of a B 4 N structure analogous to B 4 C in polycrystalline B 3 N films, which were grown at 1200 ºC by a tungsten hot-filament assisted BCl 3 -NH 3 -H 2 reaction [21].…”

mentioning

confidence: 99%

Composition and bonding structure of boron nitride B1−xNx thin films grown by ion-beam assisted evaporation

Caretti

Jiménez

2011

Chemical Physics Letters

View full text Add to dashboard Cite

show abstract

“…However, in 1971, studies by Amberger et al concluded that pure α-t boron could not be synthesized in the absence of carbon or nitrogen as an impurity [4][5][6]. These studies asserted that what was assumed to be α-t boron was actually B 50 C 2 or B 50 N 2 and the structures of these compounds were proposed.…”

Section: Introductionmentioning

confidence: 99%

“…First, the original synthesis experiments [2][3][4][5][6] were conducted using chemical vapor deposition (CVD), and it is not known what will happen if other methods are applied. Second, the work by Lee et al [7] indicates only that B 50 C 2 is more stable than pure B 50 , and does not directly disprove the existence of B 50 .…”

Section: Introductionmentioning

confidence: 99%

Effect of surface energy on the growth of boron nanocrystals

Hayami¹,

Otani²

2009

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. The surface energies of α-rhombohedral (α-rh), β-rhombohedral (β-rh), α-tetragonal (α-t), and β-tetragonal (β-t) boron were calculated from first principles to investigate their role in nano-scale crystal growth. Equilibrium shapes of boron crystals were obtained using Wulff's theorem. Our results shows that α-t boron, despite its low cohesive energy, is more stable than the other structures as a result of its low surface energy when the number of atoms is less than about 216. Since the nanowire of α-t boron that was obtained experimentally was larger than this, it was probably in a metastable state. The difference between the surface energy of the abplane and that of the ac-plane explains why the α-t nanowires grow in the c direction.

show abstract

B48B2C2 und B48B2N2, zwei Nichtmetallboride mit der Struktur des sog. I tetragonalen Bors

Cited by 76 publications

References 10 publications

Thermodynamic stability and properties of boron subnitrides from first principles

Thermodynamic stability and properties of boron subnitrides from first principles

Composition and bonding structure of boron nitride B1−xNx thin films grown by ion-beam assisted evaporation

Effect of surface energy on the growth of boron nanocrystals

Contact Info

Product

Resources

About