Can I read passive RFID tag (125/134 kHz) with a NFC tag reader, like the one on Samsung Galaxy S3 ? If not, why: maybe because of the different frequency of the NFC reader (13,56 MHz)? Any way to to excite passive RFID tag with NFC reader?
You cannot read a passive 125 KHz Tag with a NFC reader, because as you have already guessed, they operate on different frequencies.
There are passive RFID cards operating on 13.56 MHz, however, and these will read just fine on a NFC-enabled phone.
NFC/RFID Tags based on operation frequency are divided to many sections. 13.56 MHz and 125 kHz tags are the most popular.
It is obvious 125 kHz reader/writer can detect only 125 kHz tags and the same is true about the 13.56 MHz ones. 125 kHz tags usually are memory-less devices with a unique ID and middle distance detection range. These are used in many application areas like: smart parking, shop, delivery service, etc.
13.56 MHz tags usually have a memory section which enable them to store data. They are used in close distance (usually less than 10 cm) applications like: micro payment, public transportation, AFC, etc.