Table 1 Analytical conditions for acquiring EDS spectra of reference samples (SAp and PCC) in Fig. 3

Accelerating voltage

15 kV

Probe current

 < 200 nA

Specimen thickness

100 nm (approximately)

Specimen tilt

0 º

Acquisition area size

1 um × 1 um (Area acquisition mode)

Acquisition time

100 s

Number of spectrum acquisitions

20 times

Take-off angle of the EDS detector

35 º

Detector active area

60 mm²