Spectroscopic characterization of BPSCCO thin films grown by dip-coating technique C.L. Carvalho 1 , I. Guedes * Departamento de F  ısica, Universidade Federal do Cear  a, Caixa Postal 6030, Fortaleza, Cear a 60455-970, Brazil Received 21 August 2002; received in revised form 8 January 2003; accepted 14 January 2003 Abstract This work describes the growth of Bi 2x Pb x Sr 2 Ca n1 Cu n O 2nþ4 thin films by the dip-coating technique for 0:4 6 x 6 1. X-ray and Raman spectroscopic techniques were carried out in order to characterize the films at room temperature. From X-ray data it is observed that the films are multi-phased presenting phases 2201, 2212 and 2223 along with the undesirable Ca 2 PbO 4 phase. It is also observed that phase 2212 becomes dominant when Pb content increases. The Raman modes observed agree with the overall features expected for these compounds. Ó 2003 Elsevier Science B.V. All rights reserved. Keywords: BPSSCO thin films; Dip-coating technique; X-ray diffraction; Raman scattering 1. Introduction The search for high quality superconducting materials presenting transition temperatures (T c ) far above 100 K, has been the horsebattle of sev- eral researchers in the past few years. One of the most investigated superconducting system is Bi 2 - Sr 2 Ca n1 Cu n O 2nþ4 ; n ¼ 1, 2, 3 (hereafter BSCCO) [1]. Usual ceramic fabrication techniques give only mixtures with a comparable amount of low T c (80 K) 2212 and high T c (110 K) 2223 phases, and some others undesirable phases as Bi 2 (Sr,Ca) 3 - Cu 2 O y , Bi 2 Sr 2 CuO y , and Ca 2 CuO 3 . However, single-phased superconducting thin films can be made by using techniques as MBE and dc- sputtering. The major problem in obtaining phase 2223 in ceramics or single crystals is that it is highly unstable during the sintering process. An alternative to stabilize phase 2223 is by partially substituting Pb for Bi. It has already been done for ceramics and has shown good results. For in- stance, in Ref. [2] Takano et al. showed that the addition of Pb in the BSCCO system not only creates a reaction path more advantageous to the formation of and growth of phase 2223 but also increases the thermodynamical stability of this phase. This work reports on the spectroscopic study of the influence of Pb-doping in the characteristics of BSCCO thin films grown by dip-coating technique. This technique has the advantage of being simpler * Corresponding author. Fax: +55-85-2889450. E-mail addresses: carvalho@fqm.feis.unesp.br (C.L. Carv- alho), guedes@fisica.ufc.br (I. Guedes). 1 Address: Departamento de F  ısica e Qu  ımica, Universidade Estadual Paulista, Caixa Postal 31, CEP 15385-000, Ilha Solteira, SP, Brazil. 0921-4534/03/$ - see front matter Ó 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0921-4534(03)00701-9 Physica C 390 (2003) 239–242 www.elsevier.com/locate/physc