Server Administration :: Change Space Allocation For Character Columns In Database

I want to change space allocation for character columns in my database, So it will store them as 'CHAR' and not 'BYTE'.my character set is

SQL> SELECT VALUE FROM V$NLS_PARAMETERS WHERE PARAMETER='NLS_CHARACTERSET';
VALUE
----------------------------------------------------------------
AL32UTF8
SQL> alter system set NLS_LENGTH_SEMANTICS='CHAR' scope=both;

System altered.I bounced the instance just to make sure

System altered.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.

Connected to an idle instance.

SQL>
SQL>
SQL> startup
ORACLE instance started.
[code].....

And then I want to see that when I create a table with some varchar2 column,The space for it will be allocated by chars, and not by bytes! However, when I run a check of create table, this is what I get:

SQL> drop table check_char;

Table dropped.

SQL> create table check_char (some_name varchar2(10));

Table created.

SQL> select a.char_used
2 from all_tab_columns a
3 where table_name='CHECK_CHAR'
4 and a.owner='SYS';

C
-
B
SQL>

What is the reason for space allocation to remain in BYTES and not CHAR, or what else I can check?