S1
D.J. Keeble, S. Wicklein, R. Dittmann, L. Ravelli, R.A. Mackie and W. Egger
The thin films were fabricated on 10×10×0.5 mm 3
SrTiO
3
(001) single crystal substrates.
These were annealed prior to deposition at 950 °C for 46 h in air to ensure flat step terrace surfaces. A KrF excimer laser operating at 5 Hz was used for ablation and the laser fluence was between 1.00 – 2.50 J cm
-2
, with a repetition rate of 6 Hz and a spot area of 5.0×1.1 mm 2 . One film was produced using a fluence of 1.17 J cm -2 and a laser repetition rate of 30 Hz. The target-substrate distance was set at 55 mm and depositions were performed using an oxygen pressure of 0.25 mbar, with a substrate temperature of
720°C. After fabrication, the films were cooled to room temperature in at 0.25 mbar oxygen. AFM observed layer by layer growth for the films 2.00–1.67 J cm
-2
, films grown using < 1.67 J cm -2 exhibited island growth. The rate per a laser shot was approximately
0.037 nm at a laser fluence of 2.00 J cm
-2
, the films were ~200 nm thick.

S2
The XRD data from the SrTiO
3
thin films samples around the SrTiO
3
(002) peak of are depicted in Fig. S1. At least three different peaks are distinguish since the X-ray system is not perfectly monochromatic, namely CuK

 CuK


 and

Cu -K 

The observed scans contain contributions from both the film and the substrate. Hence, a satellite peak is resolved or a broadened 002-peak is observed. To quantify the expansion of the c -axis lattice constant for the SrTiO
3
thin film the CuK

 peaks of the thin film and the substrate were fitted using two Voigt functions.
Figure S1. XRD 2

–

scans of the (002) peak data from the SrTiO
3
thin films samples.

S3
Saturation trapping of positrons occurs where all positrons annihilate from the defect and sensitivity to concentration is restricted or lost completely. Defect specific trapping coefficients for neutral and negative monovacancies are typically in the range ~ 0.5-10 ×
10 15 s -1 at. [1] and the bulk positron lifetime for SrTiO
3
can be taken as

B
= 150 ps. The approximate criterion for the onset of saturation trapping is given by the expression
 
B
  d
  
B

10 , hence saturation trapping can be estimated to occur for a concentration in the range 133−7 ppm.
The DFT calculations were performed with the MIKA/Doppler package using the AP enhancement factor under GGA [2]. Strontium titanate calculations used a 1080 atom
6x6x6 supercell, with the structure determined by Nelmes et al . [3], the relaxed defect structures for V
Ti
and V
Sr
where obtained from Tanaka et al.
[4]. The PbTiO
3
calculations are described elsewhere [5]. Calculations using unrelaxed vacancy local structures were also performed for TbMnO
3
[6], SrRuO
3
[7], and LaMnO
3
[8], with a 1280 atom 4x4x4 supercell, and for Sr
3
Ru
2
O
7
[9] with a 1296 atom 3x3x3 supercell. These used room temperature orthorhombic crystal structures. The BiFeO
3
calculations were made using high temperature orthorhombic structure [10], and a 1280 atom 4x4x4 supercell. Where there is more than one oxygen site, the oxygen vacancy value given was calculated using the weighted average of the lifetimes for the individual sites.

S4
The mean positron lifetime depth profiles used to obtain the average mean positron lifetime values for the 1-4.5 keV implantation range shown in Fig. 1(a) are given in Fig.
S2.
Figure S2. VE-PALS mean positron lifetime depth profiles.
The VE-PALS lifetime component depth profiles for the 2.00–1.50 J cm
-2
films not shown in Fig. 2(ab) are given in Figs. S3 and S4.

S5
Figure S3. VE-PALS component positron lifetime depth profiles for the 2.00 and 1.83 J cm -2 films.
Figure S4. VE-PALS component positron lifetime depth profiles for the 1.50 J cm -2 film.

S6
[1] R. Krause-Rehberg, and H. S. Leipner, Positron Annihilation in Semiconductors
(Springer-Verlag, Berlin, 1999).
[2] R. A. Mackie et al.
, Phys. Rev. B 79 , 014102 (2009).
[3] R. J. Nelmes, G. M. Meyer, and J. Hutton, Ferroelectrics 21 , 461 (1978).
[4] T. Tanaka et al.
, Phys. Rev. B 68 , 205213 (2003).
[5] R. A. Mackie, A. Pelaiz-Barranco, and D. J. Keeble, Phys. Rev. B 82 , 024113
(2010).
[6] Y. Chen et al.
, J. Cryst. Growth 305 , 242 (2007).
[7] C. W. Jones et al.
, Acta Crystallogr. C 45 , 365 (1989).
[8] N. Sakai, H. Fjellvag, and B. Lebech, Acta Chem. Scand. 51 , 904 (1997).
[9] R. Kiyanagi et al.
, J. Phys. Soc. Jpn. 73 , 639 (2004).
[10] D. C. Arnold et al.
, Phys. Rev. Lett. 102 (2009).