(1. 沈陽師范大學(xué) 物理系, 沈陽 110031;
2. 中國科學(xué)院 金屬研究所 材料科學(xué)國家實驗室,
沈陽 110016)
摘 要: 根據(jù)分子動力學(xué)理論建立了非晶Ni64Pd16Al20的結(jié)構(gòu)模型,利用Recursion方法計算了Ni64X16Al20系非晶及相應(yīng)晶態(tài)的電子結(jié)構(gòu)。結(jié)果表明, Ni64X16Al20合金的非晶形成能力與過渡元素局域電子態(tài)密度的雙峰位置、電子得失形成的離子鍵及非晶與晶態(tài)合金的總結(jié)構(gòu)能差有關(guān)。 局域電子態(tài)密度的結(jié)果表明, Al與過渡元素間存在電子耦合—共價相互作用,合金元素使Ni64X16Al2合金非晶形成能力從強到弱的順序是:Ir, Pt, Rh, Pd, Au, Ag, Cu; Ni64X16Al20合金中離子鍵的存在使其非晶形成能力增強。非晶與晶態(tài)合金的總結(jié)構(gòu)能差越小的過渡元素使其形成非晶的驅(qū)動力越強, 對非晶形成越有利, 由此得出的規(guī)律與上述共價鍵的作用規(guī)律一致。
關(guān)鍵字: 非晶結(jié)構(gòu)模型; Recursion方法;電子理論; 非晶形成能力
(1. Department of Physics, Shenyang Normal University,
Shenyang 110031, China;
2. Institute of Metal Research,
Chinese Academy of Sciences,Shenyang 110016, China)
Abstract:The atom structure model of Ni64Pd16Al20 amorphous alloy was set up by using molecular dynamics theory. The electronic structure calculations of crystal and amorphous alloy Ni64X16Al20 by Recursion method reveal that the amorphous alloy forming ability is related to the location of the double-peak (or tri-peak) of local density of states (LDOS) in low energy region, electrovalent bond formed by gaining or losing electrons and the total structure energy difference of amorphous alloy Ni64X16Al20 to crystal alloy. The common conclusion drawn from LDOS and the total structure energy difference of amorphous alloy Ni64X16Al20 to crystal alloy is: when transition element Ir, Pt, Rh, Pd, Au, Ag, Cu is added into NiAl alloy, the amorphous alloy forming ability weakens in the same order. The electrovalent bond existing in Ni64X16Al20 alloy enhances the amorphous alloy forming ability too.
Key words: amorphous structure model; Recursion method; electronic theory; amorphous alloy forming ability


