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Simultaneous improvement of strength and toughness is a challenge in composite materials, as an improvement in one is generally at the expense of the other. The filler-matrix interface has a crucial role in such improvement. It appears that modification of the interfacial structure/geometry may have wider possibilities and benefits than the classical chemical bonding approach. Using a model glass-epoxy fiber-reinforced composite, we modified the regular cylindrical fiber-matrix interface by applying intermittent epoxy beads along the fiber, taking advantage of the Plateau-Rayleigh liquid instability phenomenon. Under load, the beads serve as fiber anchors in the matrix, thus exploiting the fiber strength to its maximum. During fracture, the pullout of beads through the matrix appears to dissipate more plastic deformation energy compared to the pullout of regular fibers. Fragmentation tests of beaded fibers in epoxy matrix demonstrate these failure mechanisms; single-bead fiber pullout tests with different bead sizes and surface treatments provide strength and toughness data that substantiate this approach. The concept of intermittent beading has ample possibilities for optimization. It is also scalable and therefore practical.

Sodium-based dual-ion batteries (SDIBs) are of great interest as promising candidates for large-scale energy storage due to the advantages of low cost, high cell voltage, and eco-friendliness. However, their practical applications are restricted by the unsatisfactory rate and cycling performance resulted from the sluggish Na+ reaction kinetics of anode materials. Herein, a novel SDIB is developed by using Cu3P particles confined in conductive P-doped carbon layers (Cu3P@PC) as the anode for the first time. The rational designed architecture of Cu3P@PC accelerates Na+ diffusion kinetics and alleviates volume variation effects, which endows the as-assembled Cu3P@PC//expanded graphite (EG) SDIB outstanding performance. The device delivers good rate performance up to 30 C at an upper cutoff voltage of 5.0 V, excellent cycling stability with a capacity retention of 94% over 900 cycles at 10 C, among the best results of the reported SDIBs.

Mn-containing Heuslers are important magnetic shape-memory alloys for fast and precise actuators in manufacturing, robotics, surgery, and other applications. Among the key requirements are a high magnetization and favorable thermal properties, especially a high Curie temperature. In this work, the effect of Fe and Co substitution on the structure and magnetism of Mn2NiSn alloys is investigated. The Heusler alloys have been produced by melt spinning and characterized by X-ray diffraction, magnetometry, and electron-transport measurements. It was found that Co substitution for Mn enhances the Curie temperature of Mn2NiSn and both Co and Fe substitution improve its magnetization. These improvements are accompanied by reduced thermal and magnetic hysteresis losses and by interesting structural changes, namely improved chemical order and site occupancies characteristic of quaternary (Y-ordered) Heuslers.

Alloys with nominal compositions of Mn2CrGa1-xAlx (x = 0.0, 0.2, 0.5, 1.0) have been studied by X-ray powder diffraction (XRD). Detailed structural investigation of the alloys with x = 0.2 and 0.5 has been further carried out using transmission electron microscopy (TEM). The alloys, in the typical Heusler composition, were prepared using rapid quenching and subsequent annealing. The XRD analysis revealed that a disordered cubic phase was present in the alloys with x = 0.0 and 1.0 while a spinodal decomposition with phase separation has been observed in the alloys with x = 0.2 and 0.5. TEM study confirms a segregation of two crystalline phases, one of them a cubic phase with the β–Mn prototype structure and the other a new crystalline phase with a tetragonal structure. Energy-dispersive X-ray spectroscopy (EDS) analysis was used to determine the compositions of the two crystalline phases. The mass ratio of the tetragonal phase and the β–Mn prototype cubic phase is derived as t/c ≈ 2.41 by fitting the average compositions of the two crystalline phases to the nominal composition. The orientational relationship of two crystalline structures has been determined by selected-area electron diffraction (SAED) and stereogram analysis. The structures of the two crystalline phases have been investigated by high-resolution transmission electron microscopy (HRTEM) and image simulation. The structural model of the tetragonal phase is proposed and compared with the experimental results in SAED and HRTEM studies.

Structural, magnetic, and magnetocaloric properties of iron-deficient (Nd1−xCex)YFe17 alloys in the rhombohedral Th2Zn17–type crystal structure prepared by arc-melting and vacuum annealing have been investigated. Among the investigated alloys, (Nd0.7Ce0.3)YFe17 shows the highest values of magnetic entropy change and relative cooling power, namely 5.45 J kg−1 K−1 and 504 J kg−1 for a magnetic field change of 5 T. The Curie temperature and saturation magnetization of the (Nd0.7Ce0.3)YFe17 alloy are 301 K and 162 emu/g, respectively. The absence of thermal and magnetic hysteresis with relatively high cooling capacity near room temperature suggests that Fe-deficient (Nd0.7Ce0.3)YFe17 carries significant potential for room-temperature magnetic refrigeration.

Intermetallic compounds and micro-structures in Ni–Mn–In alloy system were investigated with transmission electron microscopy, selected-area and nano-beam electron diffraction, and energy-dispersive x-ray spectroscopy. Together with two types of Heusler phases, a decagonal quasicrystalline phase and a structurally related crystallite were found in the Ni–Mn–In system. As is well-known, most of the decagonal quasicrystals are aluminum-based intermetallic phases. It is interesting to investigate the aluminum-free decagonal quasicrystalline phase as a new member of the quasicrystal family. Structural characterization was carried out on the decagonal quasicrystalline phase and the crystalline approximant in the Ni–Mn–In alloy system.

The structure of the orthorhombic Zr2Co11 phase was revisited in the present work. Selected-area electron diffraction (SAED) and high-resolution electron microscopy (HREM) techniques were used to investigate the structure. They show the orthorhombic Zr2Co11 phase has a 1-D incommensurate modulated structure. The structure can be approximately described as a B-centered orthorhombic lattice. The lattice parameters of the orthorhombic Zr2Co11 phase have been determined by a tilt series of SAED patterns. A hexagonal network with a modulation wave has been observed in the HREM image and the hexagonal motif is considered as the basic structural unit.

Single-phase Zr2Co11 nanomagnetic materials with high coercivity have been fabricated by melt spinning with subsequent annealing under Ar, N2, and vaccum. Annealing coarsens the grains and decreases the density of defects, leading to intergrain decoupling action and the enhancement of the magnetocrystalline anisotropy field of the hard magnetic phase. Therefore, coercivity increases 44.7% from 6.7 kOe for the as-spun to 9.7 kOe for the annealed which is the highest among Zr–Co alloys so far. The results show that the magnetic-hardening mechanism is primarily dominated by domain-wall pinning. In addition, annealing clearly increases the saturation magnetization. The above results indicate that Zr2Co11 has potential for fabricating rare-earth-free permanent-magnet nanocomposites.

The role of Ti and Si additions in the magnetic hardening of rapidly-quenched Zr 2 Co 11 -based nanomaterials has been investigated. Nanocrystalline Zr 17 − x Ti x Co 83 and Zr 18 Co 82 − y Si y are mainly composed of rhombohedral Zr 2 Co 11 and a small amount of orthorhombic Zr 2 Co 11 , hcp Co and cubic Zr 6 Co 23 . Ti addition decreases the mean grain size of the magnetic phases, and thus increases coercivity and energy product from 1.6 kOe and 1.9 MGOe for x = 0 to 2.6 kOe and 3.9 MGOe for x = 2, respectively. Si addition enhances the anisotropy field of the hard phase which increases the coercivity but slightly decreases the magnetization. This work shows that Ti has a positive effect on energy product through refinement of structure.

Polycrystalline Si 1 − x Cr x thin films have been prepared by magnetron sputtering followed by rapid thermal annealing (RTA) for crystallization. RTA was performed at 800 °C for 5 min, 1200 °C for 30 s and 1200 °C for 2 min, in a N 2 flow. The magnetic hysteresis loops were observed at room temperature in all the samples except for RTA at 800 °C for 5 min, and the annealing caused the decrease of saturation magnetization relative to the as-grown film. X-ray diffraction spectra and Raman spectra showed that the annealing process lead the deposited amorphous film to be crystallized and CrSi 2 phase formed. The magnetism of the films was determined by the competition between crystallinity and precipitation of diamagnetic CrSi 2 phase.

a b s t r a c t Magnetic properties and microstructure of Cr-implanted Si have been investigated by alternating gradi- ent magnetometer (AGM), superconducting quantum interference device (SQUID) magnetometer, and transmission electron microscopy (TEM). p-Type (1 0 0) Si wafers were implanted at 200 keV at room temperature with a dosage of 1 × 10 16 cm −2

This paper presents the experimental study of a solar-assisted ground-coupled heat pump system (SAGCHPS) with solar seasonal thermal storage installed in a detached house in Harbin. The solar seasonal thermal storage was conducted throughout the non-heating seasons. In summer, the soil was used as the heat sink to cool the building directly. In winter, the solar energy was used as a priority, and the building was heated by a ground-coupled heat pump (GCHP) and solar collectors alternately. The results show that the system can meet the heating–cooling energy needs of the building. In the heating mode, the heat directly supplied by solar collectors accounted for 49.7% of the total heating output, and the average coefficient of performance (COP) of the heat pump and the system were 4.29 and 6.55, respectively. In the cooling mode, the COP of the system reached 21.35, as the heat pump was not necessary to be started. After a year of operation, the heat extracted from the soil by the heat pump accounted for 75.5% of the heat stored by solar seasonal thermal storage. The excess heat raised the soil temperature to a higher level, which was favorable for increasing the COP of the heat pump.

The structure–property relationship of devitrified Pr9Fe81.5Ti2.5B7 (low-B) and Pr9Fe73.5Ti2.5B15 (high-B) nanocomposite ribbons with high coercivity has been investigated. The introduction of excessive B leads to an obvious increase of the amount of TiB2 nonmagnetic phases. TEM observation shows that TiB2 is mainly distributed in the Pr2Fe14B hard magnetic phase, which strongly hinders the domain wall movement and keeps a strong intergrain exchange coupling action among the magnetic phases. Thus, the coercivity is significantly increased by 111% from 4.6 kOe for low-B ribbons to 9.7 kOe for high-B ribbons due to increased B addition. The squareness of the demagnetization curves is also improved, simultaneously and the remanence remains almost constant. Hence, an evidently increased energy product is attained for the devitrified high-B ribbons. The distribution of nonmagnetic phases plays a key role in the improvement of the hard magnetic properties.

Nd6Fe72−xCoxB22 (x = 0, 20) rods with 1 mm diameter have been prepared by suction casting. The Nd6Fe72B22 rod is mainly composed of Nd2Fe23B3, Fe3B and a small amount of amorphous phase, whereas the Nd6Fe52Co20B22 sample is amorphous. Co addition considerably improves the glass-forming ability (GFA) of Nd6Fe72B22, which is believed to result from the large decrease of the eutectic temperature due to Co addition. Co addition promotes the formation of the Nd2Fe14B hard magnetic phase in annealed alloys, which strengthens the exchange coupling action among the magnetic phases and thus leads to a significant enhancement of the magnetic properties of the bulk nanocomposite magnets. For example, the remanence, coercivity, and energy product are increased from 3.9 kG, 1.3 kOe, and 0.9 MGOe for the Co-free alloy to 8 kG, 4.5 kOe, and 6 MGOe after Co addition, respectively.

MicroRNAs (miRNAs) are a family of 21- to 25-nucleotide, noncoding small RNAs that primarily function as gene regulators. It is surprising that these tiny molecules, so diverse and consequential in their biological functions, have been hidden for so many years. Thanks to their discovery, cancer research has found a new arena. Aided by innovative molecular techniques, the research of miRNAs in oncology has progressed rapidly in recent years. miRNA abnormalities are becoming an emerging theme in cancer research. Specific functions of miRNAs, many of which are relevant to cancer development, are becoming apparent. The value of miRNAs in cancer classification and prognostication is being explored, and new therapeutic strategies targeting miRNAs are being developed. Because there is great promise that miRNA research will provide breakthroughs in the understanding of cancer pathogenesis and development of new valuable prognostic markers, pathologists should be adequately informed of this rapidly progressing field. Here, we offer a review on the basics of miRNA biology and the emerging role of miRNA in cancer pathogenesis, classification, and prognostication, including highlights of the involvement of specific miRNAs in different tumor types.

The effect of refractory element addition on phase transformation, crystallization behavior and magnetic properties of Pr 8.5 Fe 81.5 B 10 (addition-free) and Pr 8.5 Fe 81.5 M 2 B 10 (M=V, Cr, Nb, Zr, Ti) ribbons has been investigated. The annealed addition-free ribbon as well as the samples with V or Cr additions are mainly composed of the metastable Pr 2 Fe 23 B 3 phase, whereas annealed ribbons with Nb, Zr or Ti additions primarily consist of Pr 2 Fe 14 B and a minor amount of Fe 3 B/boride. The complete suppression of the metastable Pr 2 Fe 23 B 3 phase due to Nb, Zr or Ti additions leads to a significant enhancement of the magnetic properties. For example, the remanence, the coercivity and the energy product are remarkably increased from 2.5 kG, 0.4 kOe and 0.2 MG Oe for the addition-free material to 9.2 kG, 4.7 kOe and 7.6 MG Oe for the specimens with Nb addition. The successful elimination of the metastable Pr 2 Fe 23 B 3 phase is believed to profit from two factors: (a) Nb, Zr or Ti atoms substitute the Pr site, comparatively increase the Pr content, and thus inhibit the nucleation of Pr-lean Pr 2 Fe 23 B 3 phases, and (b) the formation of Nb, Zr, or Ti borides consumes some part of B, which hinders the generation of the B-rich Pr 2 Fe 23 B 3 phase.

Nanocomposite (Nd,Pr) 2 Fe 14 B/α-Fe magnets were prepared by crystallizing the amorphous melt-spun ribbons. The effects of Nb and Zr additions on the crystallization behavior, microstructure, and magnetic properties of (Nd 0.4 Pr 0.6 ) 8.5 Fe 85.5− x − y Nb x Zr y B 6 ( x = 0 , 0.5 , 1 ; y = 0 , 0.5 , 1 ) alloys were studied. The microstructure and phase analysis shows that for (Nb,Zr)-free ribbons, α-Fe first precipitates, followed by the crystallization from amorphous to metastable phase before final transformation to the 2 : 14 : 1 phase and α-Fe. However, the combined Nb and Zr additions can increase the precipitating temperature of α-Fe, restrain the formation and growth of α-Fe, avoid the formation of metastable phase, refine and uniform the grain size, and thus greatly enhance intergrain exchange coupling between the hard and soft magnetic phases (verified by δM – H plot). After optimal thermal treatment, the coercivity and maximum energy product increase from 411 kA/m, 107 kJ/m 3 for (Nd 0.4 Pr 0.6 ) 8.5 Fe 85.5 B 6 sample to 534 kA/m, 144 kJ/m 3 for (Nd 0.4 Pr 0.6 ) 8.5 Fe 84.5 Zr 0.5 Nb 0.5 B 6 sample, respectively.

The effects of CuO and V2O5 additions and the particle sizes of precursor materials on the microstructure and relative initial permeability of low firing temperature NiCuZn ferrites were investigated. It was found that additions of CuO and V2O5 contribute to the grain growth and densification of matrix in the sintering process, which were favorable for increase in relative initial permeability. The relative initial permeability was also strongly affected by the average particle size of precursor materials. Through using precursor materials of 0.8 μm average particle size and adding 10 mol% CuO and 0.20 mol% V2O5, for the low firing temperature NiCuZn ferrite, very high relative initial permeability of 1417 can be achieved at the frequency of 1 MHz.

The effect of annealing treatment on the magnetic properties and microstructure of Nd 12.0 Dy 2.8 Fe 74.7 Co 3.4 Cu 0.2 B 6.9 magnets has been investigated. It is found that intrinsic coercivity i H c is improved with the increase of annealing temperature, and the maximum value is attained at 480 °C. i H c is rapidly decreased with a further increase of annealing temperature. For a given annealing temperature of 480 °C, i H c is increased with the increase of annealing time, and the maximum value is achieved at 2 h. It almost remains constant when annealing time is further increased. However, while the annealing treatment has little effect on remanence B r . It is certain that the increase of i H c for the annealed magnets arises from the more smooth grain boundaries of the RE 2 Fe 14 B phases and the more continuous/uniform distribution of RE-rich phases. The great change of microstructure in the annealed magnets can be explained using atomic diffusion theory.

The effects of Nb and Zr additions on the microstructure, phase transformation and magnetic properties of melt-spun (Nd,Pr)2Fe14B/α-Fe nanocomposite magnets have been investigated. The results show that, for (Nd0.4Pr0.6)8.5Fe85.5B6 ribbons, the metastable (Nd,Pr)3Fe62B14 phase precipitates after the initial crystallization of α-Fe and then decomposes into the final mixture of (Nd,Pr)2Fe14B and α-Fe. For (Nd0.4Pr0.6)8.5Fe84.5Zr0.5Nb0.5B6 ribbons, however, (Nd,Pr)2Fe14B and α-Fe phases precipitate simultaneously from the amorphous phase, which can avoid the formation of metastable phase and refine the grains. During crystallization, Nb and Zr atoms partly enter the 2:14:1 structure and replace rare earth atoms, which increases the volume content of hard magnetic phase. The intrinsic coercivity of (Nb,Zr)-free samples increases from 411 to 534 kA/m for (Nb,Zr)-doped samples, and the maximum energy product increases from 107 to 144 kJ/m3 correspondingly. In addition, due to the Nb and Zr addition, the coercivity mechanism for the ribbons is changed from nucleation of reverse domains to the pinning of domain walls.

The structure and magnetic properties of arc-melted (Sm,Pr) 2 Fe 14 Ga 3 C 2 compounds and as-spun ribbons were studied. X-ray diffraction results show that (Sm 1−x Pr x ) 2 Fe 14 Ga 3 C 2 compounds are single-phase with the Th 2 Zn 17 -type structure. With the increase of x from 0 to 0.5, a monotonic increase of the saturation magnetization from 93 to 104 emu g −1 was obtained in the compounds. All compounds of (Sm 1−x Pr x ) 2 Fe 14 Ga 3 C 2 studied in this work exhibit an easy c -axis anisotropy at room temperature. A small amount of Pr substitution for Sm increases the remanence of (Sm 1−x Pr x ) 2 Fe 14 Ga 3 C 2 ribbons from 0.49 to 0.57 T due to an increase in the saturation magnetization of the (Sm 1−x Pr x ) 2 Fe 14 Ga 3 C 2 phase, and then the remanence falls off slowly with x because of the appearance of (Sm,Pr)Fe 2 . The decrease of the coercivity with x has been found to arise from the decrease in the anisotropy field of the Sm 2 Fe 14 Ga 3 C 2 phase due to the replacement of Sm by Pr. A maximum energy product of 71 kJ m −3 for (Sm 1−x Pr x ) 2 Fe 14 Ga 3 C 2 ribbons with x =0.2 was obtained at a wheel speed of 17.5 m s −1 .

Melt-spun Nd 13 Dy 2 Fe 77− x Co x C 6 B 2 ( x =0, 5, 10, 15, 20) ribbons with a high coercivity more than 2 T have been obtained. It was found that the ribbons quenched at the optimum wheel speed 15 m/s (as-spun ribbons) mainly consist of ferromagnetic 2 : 14 : 1 phase and paramagnetic NdC 2 phase, and the ribbons spun at 25 m/s and subsequently annealed at 973 K for 15 min (as-annealed ribbons) are primarily composed of the magnetic 2 : 14 : 1 and 2 : 17 phases. The magnetization process of as-spun ribbons controlled by a pinning of the domain wall is different from that of as-annealed ribbons determined by a nucleation of the reverse domain. This significant difference originates possibly from the existence of paramagnetic NdC 2 phase acting as a pinning center in as-spun ribbons. In the as-annealed ribbons, the substitution of Co for Fe leads to increase of remanence ( μ 0 M r ), maximum energy product ((BH) max ) from 0.67 T, 9.7 MGOe for x =0 to 0.84 T, 14.4 MGOe for x =10, respectively. A coercivity of 2.74 T is obtained for as-quenched Nd 13 Dy 2 Fe 77− x Co x C 6 B 2 ( x =0) ribbons.

Nanocomposite Nd 3.6 Pr 5.4 Fe 83 Co 3 B 5 ribbons were prepared by direct melt spinning at different wheel speeds. The hysteresis loop of the ribbons prepared at wheel speed V=20 m/s shows a single hard magnetic behavior with high coercivity. The values of remanence M r =11.3 kG s , intrinsic coercivity i H c =6.0 kOe and energy product ( BH ) max =17.2 MG Oe are obtained at room temperature. Transmission electron microscopy and magnetic force microscopy have been employed to image the microstructure and magnetic domains in the ribbons. Due to the unnegligible inter-grain exchange coupling, interaction domains are observed. The shape of the demagnetization curve in the second quadrant at different temperature gives more information about inter-grain exchange coupling. The coercivity mechanism is discussed.

The effect of Co substitution for Fe on the structure and magnetic properties of Cu doped Sm2Fe15-xCoxSi2C (x = 0-5) compounds with the Th2Zn17 structure have been investigated. The substitution of Co leads to a contraction of the unit-cell. The Co content dependence of saturation magnetization M-s exhibits a maximum value of 114.1 emu/g at x = 4. The Curie temperature Te increases monotonically with increasing Co concentration from 567 K for x = 0 to 723 K for x = 5. The room temperature anisotropy field H-A is found to slightly decrease with increasing Co content. The intrinsic coercivity of melt-spun Cu doped Sm2Fe15CoxSi2C (x = 0-5) ribbons decreases as the Co content is increased. A remanence of 6.23 kG and a maximum energy product of 7.2 MG Oe at room temperature is obtained in the sample of x = 3. The coercivity mechanism for melt-spun ribbons is mainly controlled by the nucleation of reverse domains. (C) 2001 Elsevier Science B.V. All rights reserved.

The phase evolution and magnetic properties of melt-spun Pr9Fe86−xCoxB5 (x=0,6,10,12,14,16) nanocomposites have been investigated. It was found that substitution of Co for Fe obviously raises the magnetization (M, H=6.5T), from 1.50 T for x=0 to 1.80 T for x=12. At the same time, the remanence (Mr), intrinsic coercivity (iHc) and maximum energy product (BHmax) changes from 0.96 T, 5.69 kOe, 11.8 MGOe for x=0 to 1.15T, 6.33 kOe, 17.3 MGOe for x=12, respectively. Further substitution of Co for Fe results in a decrease of Mr and BHmax because of the presence of minor amounts of 1:5 and 2:17 phases. Thermomagnetic analysis shows that the Co atoms enter into both the magnetically hard and soft phases. The Curie temperature of the hard magnetic phase increases linearly by increasing Co-substitution at the rate of ΔTc=9°C/at% Pr.

Microstructure and magnetic properties of melt-spun nanocomposite magnets with nominal compositions of (Nd1-xPrx)(9)Fe86B5 (x = 0-1) were investigated. Substitution of Nd by Pr could significantly improve the hard magnetic properties of the nanocomposite magnets; the intrinsic coercivity (H-i(c)) and the maximum magnetic energy product ((BH),,,) increase from 414kA/m and 124kJ/m(3) for x = 0 to 493 kA/m and 152 kJ/m(3) for x = 0.6, respectively. Further substituting Nd by Pr (x >0.6) strongly weakens exchange-coupling interaction between magnetically hard and soft phases. (C) 2001 Elsevier Science B.V. All rights reserved.

Familial juvenile hyperuricemic nephropathy (FJHN), is an autosomal dominant renal disease characterized by juvenile onset of hyperuricemia, gouty arthritis, and progressive renal failure at an early age. Using a genomewide linkage analysis in three Czech affected families, we have identified, on chromosome 16p11.2, a locus for FJHN and have found evidence for genetic heterogeneity and reduced penetrance of the disease. The maximum two-point LOD score calculated with allowance for heterogeneity (HLOD) was 4.70, obtained at recombination fraction 0, with marker D16S3036; multipoint linkage analysis yielded a maximum HLOD score of 4.76 at the same location. Haplotype analysis defined a 10-cM candidate region between flanking markers D16S501 and D16S3113, exhibiting crossover events with the disease locus. The candidate interval contains several genes expressed in the kidney, two of which—uromodulin and NADP-regulated thyroid-hormone–binding protein—represent promising candidates for further analysis.

We have succeeded in preparing magnetically anisotropic SmCo5 ribbons with high permanent performance by single-roller melt spinning at low wheel velocity. The anisotropy is associated with a crystallographic texture formed during melt-spinning process, with the c-axis parallel to the longitudinal direction of the ribbons. The formation of the crystallographic texture is attributed to a directional solidification process resulting from a thermal gradient. A remanence of 9.1 kG, remanence ratio of 0.9, intrinsic coercivity of 16.2 kOe and energy product of 18.2 MGOe at room temperature are obtained in the melt-spun and subsequently annealed SmCo5 ribbons prepared at 5 m/s. (C) 2000 Elsevier Science B.V. All rights reserved.

The structural and magnetic properties of melt-spun Sm1 + delta Co-5 ribbons (delta = 0, 0.05, 0.1, 0.15 and 0.2) prepared using low wheel speed (nu = 5 m s(-1)) have been studied by X-ray diffraction and magnetic measurement. A high degree of texture, in which the c-axis is parallel to the longitudinal direction of the ribbons, has been observed for the first time. Thermal stability of coercivity can be improved by the addition of Sm. For delta = 0.15, the coercivity is above 20 kOe at RT and up to 4.4 kOe at 300 degrees C. The remanance M-r is found to depend sensitively on the angle between the applied fields and the longitudinal direction of ribbon, and a maximum energy product of about 18.2 MGOe has been achieved for delta = 0.1 ribbons. (C) 1999 Elsevier Science S.A. All rights reserved.

Chemical vapor deposited (CVD) diamond films (DF) were prepared on P-type oriented Si substrates. The films were implanted with 140 keV N+ to doses of 5 x 10(14) similar to 1 x 10(16)cm(-2), respectively. Under the implantation, the DF becomes more and more disordered with each increasing dose. Scanning electronic microscopy (SEM) and Raman measurements reflect the amorphization process. Combining the electrical resistance measurements, it is clear that polycrystalline DF has a higher threshold dose of amorphization than that for bulk ones. The damages induced by implantation can be partially removed by annealing when the dose is below the critical value. Larger doses of implantation produce amorphous carbon which can transform into micro-polycrystalline graphite during annealing. Thus, the conductivity is increased dramatically. However, for smaller dose N+ implanted samples, while annealing was performed, the samples become comparable conductive for the activation of N dopants. (C) 2000 Elsevier Science S.A. All rights reserved.