Simple Perovskite AMnO3 211 Pulsed Laser Deposition

The manganite thin films have been mainly prepared using the PLD technique [1,2,14,15]. The principle of this technique is relatively simple. A pulsed laser beam ablates a dense ceramic target of the desired material. In the presence of a background gas (usually oxygen), a plasma is produced and condenses on the heated substrate. Typical lasers used for manganite are excimer Ultra violet (UV) with KrF at A = 248 nm [15-17], XeCl at A = 308 nm [18], or ArF at A = 193 nm [19]. A frequency tripled Nd-YAG at A = 355 nm [20] or quadrupled Nd-YAG at A = 266 nm [21] may also be used. A cross-beam deposition scheme utilizing two Nd-YAG lasers was also used to grow Pr0 65Ca0 35MnO3 thin films on LaAlO3 [22]. However, the utilization of high oxygen pressure during PLD growth prevents the use of a reflection high energy electron diffraction (RHEED) system in order to control in-situ the different stages of the growth. By a more oxidizing gas (atomic oxygen, ozone, ...) and a differential pumping system, the electron path in the high pressure oxygen atmosphere can be reduced, and thus the specular beam of the RHEED can be monitored in order to observe the oscillations (see Fig. 1 for a typical experimental setup). High quality manganite thin films were fabricated in this way [23,24]. A persistent intensity of the RHEED is observed and the roughness of the films is low, around one unit cell [23].

Table 1. Examples of various CMR thin films.

Composition

Growth method

Substrates used

Ref.

La07Ca03MnO3

0 0

Post a comment