Can you sacrifice a permanent that was just returned to the battlefield by a flicker effect in the same turn?

When a permanent is 'flickered' — exiled and returned to the battlefield — it enters as a completely new game object. Under CR 400.7, an object that moves zones loses all memory of and connection to its previous existence. This means summoning sickness, previous counters, and any other history are reset, but it also means there is no special restriction preventing you from sacrificing it right away.

Summoning sickness (CR 302.6) only prevents a creature from attacking or using activated abilities with the tap or untap symbol. It does not prevent a permanent from being sacrificed. Sacrificing is a cost or effect initiated by a spell or ability, not an action the permanent itself takes, so summoning sickness is irrelevant to whether something can be sacrificed.

There is no 'freshness' restriction in the rules that prevents a permanent from being sacrificed the same turn it entered the battlefield, whether flickered or not. As long as you have a spell or ability that lets you sacrifice it (like an Altar or a spell requiring a sacrifice cost), you can do so immediately upon the permanent resolving onto the battlefield.

Example: You control Phyrexian Altar and use Momentary Blink to flicker your Siege-Gang Commander. It returns to the battlefield (and its ETB trigger goes on the stack). Before or after that trigger resolves, you can immediately sacrifice Siege-Gang Commander to Phyrexian Altar for one red mana — no waiting required.