Y
,
ong GAO
,
Shaoqing ZHANG
,
Bocao LIU
材料科学技术（英文）
The melt-spun Nd8Fe85Nb1B6 ribbon was prepared by the single roller method with the tangential speed of 20 m/s. A mixture of Nd2Fe14B and alpha -Fe phases with the average crystalline grain size of about 20 nm was found to exist in the as-quenched ribbons. The initial magnetization curve of the nanocomposite Nd8Fe85Nb1B6 ribbon can be divided into four sections by the inflection points on it. The magnetically hardening mechanism corresponding to each section was investigated. The initial susceptibility of the Nd8Fe85Nb1B6 ribbon is higher than that of the Nd15Fe85B9 powder, which may be attributed to the reversible magnetization rotation in the central region not influenced by the exchange-coupling effect within the alpha -Fe grains. The above-mentioned magnetization rotation leads to the formation of equilibrium 180 deg. domain walls at the boundaries of the alpha -Fe grains. With the increase of applied field, these domain walls are compressed reversibly towards the Nd2Fe14B grains and eventually invade into them. The irreversible movement of the domain walls in the Nd2Fe14B grains accounts for the steepest growth of magnetization with the applied field. Finally, the magnetically inhomogeneous "core regions" are formed in the Nd2Fe14B grains, and the magnetization rotation in these "core regions" indicates the end of the whole initial saturation process.
关键词:
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
Philosophical Magazine
The error of Equation (15b) in my article [Z.D. Zhang, Phil. Mag. 87 (2007) p.5309] in the application of the Jordan-Wigner transformation does not affect the validity of the putative exact solution, since the solution is not derived directly from that equation. Other objections of Perk's comment [J.H.H. Perk, Phil. Mag. 89 (2009) p.761] are the same as those in Wu et al.'s comments [F.Y. Wu et al., Phil. Mag. 88 (2008) p.3093; p.3103], which do not stand on solid ground and which I have sought to refute in my previous response [Z.D. Zhang, Phil. Mag. 88 (2008) p.3097]. The conjectured solution can be utilized to understand critical phenomena in various systems, whereas the conjectures are open to rigorous proof.
关键词:
3D Ising model;exact solution;conjecture;critical phenomena;ferromagnetism;magnetic phase transition;model;analyticity
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
Physics Letters A
In a magnetic system, consistent with Griffiths analyticity requirements one can parameterize the equation of state near criticality by writing H = r(beta delta)h(theta), T = rt(theta) and the magnetization M = r(beta)m(theta), where T is measured from the critical temperature. For the insulating ferromagnet CrBr(3), the experimental data of Ho and Litster [J.T. Ho, J.D. Litster, Phys. Rev. Lett. 22 (1969) 6031 is well fitted by m(theta) as a linear function of theta [P. Schofield, J.D. Litster, J.T Ho, Phys. Rev. Lett. 23 (1969) 1098]. Also Ho and Litster give beta = 0.368, gamma = 1.215 and delta = 4.3. Those critical experiments are very close to the recent 31) king results of Zhang [Z.D. Zhang, Philos. Mag. 87 (2007) 5309], namely beta = 3/8, gamma = 5/4 and delta = 13/3. We therefore predict that m(theta) will be proportional to theta as a fingerprint of the 3D Ising Hamiltonian. (C) 2009 Elsevier B.V. All rights reserved.
关键词:
Critical-point effects;Critical exponents;Ising model;Criticality;Ferromagnet;Magnetic equation of state;critical exponents
Philosophical Magazine
This is a Response to a recent Comment [F.Y. Wu, B.M. McCoy, M.E. Fisher et al., Phil. Mag. 88 (2008)] on the conjectured solution of the three-dimensional (3D) Ising model [Z.D. Zhang, Phil. Mag. 87 5309 (2007)]. Several points are made: (1) Conjecture 1, regarding the additional rotation, is understood as performing a transformation for smoothing all the crossings of the knots. (2) The weight factors in Conjecture 2 are interpreted as a novel topologic phase. (3) The conjectured solution and its low- and high-temperature expansions are supported by the mathematical theorems for the analytical behavior of the Ising model. The physics behind the extra dimension is also discussed briefly.
关键词:
critical temperatures;lattices;analyticity;bounds
