how to make circular material button in flutter code example

Example 1: circular button in flutter

Container(
                      width: 90,
                      height: 90,
                      child: RaisedButton(onPressed: (){
                      },
                        color: Colors.deepOrange,  
                        textColor: Colors.white,
                        shape: CircleBorder(side: BorderSide.none),
                        child: Text('Login',style: TextStyle(
                            fontSize: 20.0
                        ),
                        ),
                      ),
                    )

Example 2: A circuler border button in flutter

Padding(  padding: EdgeInsets.only(left: 150.0, right: 0.0),  child: RaisedButton(    textColor: Colors.white,    color: Colors.black,    child: Text("Search"),    onPressed: () {},    shape: new RoundedRectangleBorder(      borderRadius: new BorderRadius.circular(30.0),    ),  ),)