Smooth rotate use joystick

i have a game object that i want to rotate when player move the joystick to left and right.
i use single joystick from standard asset mobile . i use

void Update(){

xposisi = GameObject.Find("Single Joystick").GetComponent<Joystick>().position.x ;


transform.eulerAngles = new Vector3(0,0, xposisi * 10); ;
}

but that rotate doesn’t smooth. i need more smooth rotate. what should i do?
thankyou for all respons and im sorry for my bad english

Try like this:

Quaternion eulerRot = Quaternion.Euler(0.0f, 0.0f, xposisi);
transform.rotation  = Quaternion.Slerp(transform.rotation, eulerRot, Time.deltaTime * 10);