Galaxy Y is restarting again and again after factory reset.

I formatted my phone due to "low space in memory", after I click on factory data reset and now my phone is restarting over and over. I waited for 5 minutes but it was not turning on then I removed my battery and I restart it but it was showing samsung's logo only. I also tried to enter into recovery mode for factory reset by pressing volume down+power button, but same thing happened restarting again & again showing only Samsung logo