[1] Yaldram K and Khan M A 1992 J. Catal. 136 279

[2] Ziff R M, Gulari E and Barshad Y 1986 Phys. Rev.
Lett. 56 2553

[3] Brosilow B J and Ziff R M 1992 J. Catal. 136
275

[4] Ahmad W and Baloach M K 2007 Appl. Surf. Sci.
25 38447

[5] Ahmad W and Baloach M K 2006 Chin. Phys. Lett.
23 1034

[6] Meng B, Weinberg W H and Evans J W 1993 Phys. Rev. E
48 3577

[7] Kalid M, Qaisrani A U and Ahmad W 2005 Chin. Phys.
Lett. 22 1533

[8] Loscar E S and Albano E V 2002 Phys. Rev. E 65
066101

[9] Frink Th, Dath J P, Basset M R, Imbihl R and Ertl G 1991
Surf. Sci. 245 96

[10] Meakin P J 1990 Chem. Phys. 93 2903

[11] Khan K M and Ahmad W 2002 J. Phys. A: Math. Gen.
35 2713

[12] Khan K M and Kaldram K 2000 Surf. Sci. 445
186

[13] Campbell C T, Ertl G, Kuipers H and Segner G J 1980
Chem. Phys. 73 5862

[14] Hua D Y and Ma Y Q 2002 Chin. Phys. Lett. 4
534

[15] Khan K M, Ahmad W and Iqbal K 2003 Int. J. Mod.
Phys. C 14 1413

[16] Ahmad W, Parvez M, Musa K B and Khalid M 2006
Physica A 364 307

[17] Waqar Ahmad, Parvez M, Musa Kaleem Baloach, Qaisarani A U
and Khalid M 2006 Appl. Surf. Sci. 25 3600

[18] Ahmad W, Baloach M K and Parvez M 2006 Chin. J.
Phys. 44 440