GLORIA — GEOMAR Library Ocean Research Information Access

1

Digitale Medien

Magnetic properties of Dy2Fe17 and Dy2Fe17C : The 5th Joint MMM−Intermag Conference (1991)

Tang, N. ; Liang, J. Z. ; Yu, Mingjun ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 70 (1991), S. 6152-6153

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: The magnetic properties of Dy2Fe17 and Dy2Fe17C have been reported. The expansion of the lattice and increase of Curie temperature Tc and magnetization M have been found for Dy2Fe17C, and compared with Dy2Fe17. From the study of 57Fe Mossbauer spectra, we found that the average hyperfine field of Dy2Fe17C is about 5 T larger than that of Dy2Fe17. The isomer shift of the 4f site is smaller for Dy2Fe17C compared with Dy2Fe17.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.350026

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

2

Digitale Medien

Anomalous temperature dependence of photoluminescence from InAs quantum dots (2000)

Jiang, W. H. ; Ye, X. L. ; Xu, B. ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 88 (2000), S. 2529-2532

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: Self-assembled InAs quantum dots are fabricated on a GaAs substrate by molecular beam epitaxy. The dots are covered by several monolayers of In0.2Ga0.8As before a GaAs cap layer and an in situ postgrowth annealing is performed to tune the emission to higher energy. The temperature dependence of photoluminescence from this structure demonstrates a slower redshift rate of the peak position, a gradual broadening of the linewidth and an abnormal enhancement of integrated intensity as the temperature is increased from 15 to 300 K. These phenomena are closely related to the introduction of an InGaAs layer and to the intermixing of In and Ga atoms during annealing. We propose a model to explain the unusual increase in PL intensity, which fits the experimental data well. © 2000 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.1288231

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

3

Digitale Medien

A neutron powder diffraction study of the system La2(Co1−xFex)16Ti for x=0.0, 0.2, and 0.4 (1999)

Liang, J. K.

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 86 (1999), S. 1226-1229

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: The nuclear and magnetic structures of La2(Co1−xFex)16Ti have been studied by neutron powder diffraction for the compositions x=0.0,0.2,0.4. The compound crystallizes with the symmetry of space group R3¯m. Site occupancy results show significant departures from a purely statistical distribution, with the Ti atoms located in sites which interact weakly with La, and with the Co atoms occupying preferentially the sites with strong La interaction. These results are consistent with the enthalpies of formation of equiatomic alloys of rare earth and 3d elements. The spin ordering at all compositions and temperatures is ferromagnetic. At room temperature the moments are aligned along the c axis for the compositions x=0.0 and x=0.2, and form an angle of about 57° with c for x=0.4. This tilt angle is a function of temperature and the moment is aligned along c at 11 K, moving gradually towards the a,b plane as the temperature increases. © 1999 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.370875

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

4

Digitale Medien

Effect of growth temperature on luminescence and structure of self-assembled InAlAs/AlGaAs quantum dots (2001)

Liu, H. Y. ; Xu, B. ; Qian, J. J. ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 90 (2001), S. 2048-2050

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: The effect of growth temperature on the optical properties of self-assembled In0.65Al0.35As/Al0.35Ga0.65As quantum dots is studied using photoluminescence and electroluminescence spectra. With the growth temperature increasing from 530 to 560 °C, the improvement of optical and structural quality has been observed. Furthermore, edge-emitting laser diodes with three stacked InAlAs quantum dot layers grown at different temperature are processed, respectively. For samples with quantum dots grown at 560 °C, the continuous wave operation is obtained up to 220 K, which is much higher than that of ones with InAlAs islands grown at 530 °C and that of the short-wavelength quantum-dot laser previously reported. © 2001 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.1388021

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

5

Digitale Medien

Structural transformations of Bi2CuO4 induced by mechanical deformation (1999)

Chen, X. L. ; Liang, J. K.

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 85 (1999), S. 3155-3158

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: Structural transformation of α-Bi2CuO4 (a=8.4996 Å, c=5.8172 Å, space group P4/ncc) during ball milling was investigated by powder x-ray diffraction and thermal analysis. It is shown that α-Bi2CuO4 first transforms into an amorphous phase; and then transforms into a new phase (designated by β-Bi2CuO4) with milling time. The new phase appears to be isostructural to (La,Sr)2CuO4 and has a tetragonal cell with cell parameters a=3.869 and c=13.83 Å. It is a metastable phase which can transform back into α-Bi2CuO4 at 650 °C. No superconductivity was observed above 5 K for both as-milled samples and oxygen-annealed β-Bi2CuO4. © 1999 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.369692

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

6

Digitale Medien

Study of the orientational relaxation dynamics in a nonlinear optical copolymer by means of a pole and probe technique (1996)

Michelotti, F. ; Toussaere, E. ; Levenson, R. ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 80 (1996), S. 1773-1778

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: We report measurements on the isothermal relaxation dynamics of the electro-optic coefficient of electric field poled polymeric films. The studied copolymer is a side-chain Disperse Red 1/poly–methyl–metacrylate combination. The isothermal relaxation is shown to follow a Kohlrausch–Williams–Watts stretched exponential dependence, whose parameters are strongly dependent on temperature. The average decay constant is shown to follow an Arrhenius temperature dependence below the glass transition Tg, while it is described by a Vogel–Fulcher–Tamann–Hesse above Tg. The values of the decay constant confirm a much better stability of the polymer orientation with respect to guest-host systems. The relaxation is shown to be due to a broad distribution of relaxation rates, the width of which can be qualitatively described by an empirical relation, which has already been used for guest-host systems. The measurement technique permits monitoring relaxation in a standard dielectric relaxation configuration and performing unconventional poling of the samples. © 1996 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.362987

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

7

Digitale Medien

Crystal structure and magnetism of LaCo13−x−yFexSiy compounds (1996)

Rao, G. H. ; Liang, J. K. ; Zhang, Y. L. ; [weitere]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 80 (1996), S. 336-341

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: The crystal structure and magnetic properties of LaCo13−x−yFexSiy compounds were investigated by means of x-ray powder diffraction and magnetization measurements. The substitution of Si for Co induces an order–disorder transition from the cubic NaZn13-type to its tetragonal derivative structure, while the substitution of Fe for Co does not induce such a phase transition. After annealing treatment, the homogeneous range of the cubic phase is narrowed and that of the tetragonal phase is extended. From crystallographic and thermodynamic points of view, the sta- bility of the cubic and the tetragonal phases is discussed. The measured magnetic moment of LaCo13−x−yFexSiy coincides well with the theoretical prediction based on the magnetic valence model. Within the framework of this model, LaCo13−x−yFexSiy compounds can be considered as strong ferromagnets and their magnetic moment can be theoretically predicted. The composition dependence of Curie temperature is discussed within the mean field approximation. At higher iron concentration the decrease of Curie temperature with Fe concentration might be attributed to the increase of the number of antiferromagnetically coupled Fe–Fe pairs and the decrease of the ferromagnetic coupling between transition metal atoms. © 1996 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.362786

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

8

Digitale Medien

Interfacial reactions and thermal stability of ultrahigh vacuum deposited multilayered Mo/Si structures (1996)

Liang, J. M. ; Chen, L. J.

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 79 (1996), S. 4072-4077

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1089-7550

Quelle: AIP Digital Archive

Thema: Physik

Notizen: Interfacial reactions and thermal stability of ultrahigh vacuum deposited multilayered Mo/Si structures have been investigated by high resolution transmission electron microscopy in conjunction with fast Fourier transform and autocorrelation function analysis. For samples with nominal atomic ratios Mo:Si=1:2 and 3:1, well defined multilayered Mo/Si structures were obtained after annealing at 250 °C for 30 min. On the other hand, distinct multilayered MoSi2/Si structure was formed only for Mo:Si=1:2 samples after annealing at 650 °C for 1 h. Multiphases were observed to simultaneously form in samples annealed at 400–500 °C. After 600 °C annealing for 1 h, tetragonal MoSi2 was the only silicide phase observed for the Mo:Si=1:2 samples, whereas both tetragonal and hexagonal MoSi2 were present in Mo:Si-3:1 samples. The stability of the multilayered Mo/Si structures was found to depend critically on the atomic ratios of constituent elements, bilayer period, and annealing conditions. The results are interpreted in terms of the delicate balance among intermixing of constituent atoms, silicide formation, and crystallization of silicon. © 1996 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.361835

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

9

Digitale Medien

Crystal structure and electronic transport property of perovskite manganese oxides with a fixed tolerance factor (1997)

Sun, J. R. ; Rao, G. H. ; Liang, J. K.

Woodbury, NY : American Institute of Physics (AIP)

Applied Physics Letters 70 (1997), S. 1900-1902

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1077-3118

Quelle: AIP Digital Archive

Thema: Physik

Notizen: The structural and electronic transport properties of ABO3-type compounds La2/3−xRxCa1/3MnO3(R=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Er, and Tm) with a fixed tolerance factor of t=0.91137 is studied. Similar structure deformation, characterized by the nearly constant average Mn–O, A–O distances and Mn–O–Mn bond angles, is observed in different compounds. The metal–semiconductor transition shows a strong R dependent feature. The transition temperature decreases monotonously from 187 to 77.6 K as R varies from Tm to Pr, with a corresponding maximum resistivity ranging from 2.34 to 6.17×104 Ω cm. Very different magnetoresistance effects are also observed in this series of compounds. By assuming the presence of inhomogeneous local lattice distortions due to ions with different sizes at A sites and their mismatch with B ions, the lattice effects can be understood qualitatively. © 1997 American Institute of Physics.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.118725

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

10

Digitale Medien

Bulk superconductivity with Tc (zero) up to 95 K in a Tl0.5Pb0.5Ca0.9Ce0.1Sr2Cu2 oxide with an Y1Ba2Cu3Oy-like structure (1989)

Wu, P. T. ; Liu, R. S. ; Liang, J. M. ; [weitere]

Woodbury, NY : American Institute of Physics (AIP)

Applied Physics Letters 54 (1989), S. 2464-2466

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1077-3118

Quelle: AIP Digital Archive

Thema: Physik

Notizen: Bulk superconductivity with Tc (zero) up to 95 K in a Tl0.5Pb0.5Ca0.9Ce0.1Sr2Cu2 oxide with an Y1Ba2Cu3Oy -like structure was observed. Single-phase samples, tetragonal in structure with a=0.380±0.001, c=1.195±0.001 nm, and of P4/mmm space group, were prepared. The results represent the first case where Ce substitution significantly raised the Tc of a known compound. The samples were remarkably homogeneous both in composition and structure. The compounds were highly reproducible and stable. The preparative conditions were found to be much less stringent than those of other copper-based high Tc superconductors.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1063/1.101536

Permalink

	Standort	Signatur	Einschränkungen	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext