Nav bar button icon size

I have an ion-view that I am placing a nav button on. I am noticing however that the size of the icon is shrunk. I have another ion-view that I navigate to and placing the same button there produces a bigger icon on the screen. Any guidance why this is happening and how I can get the larger size icon to show up. The relevant code:

<ion-view view-title="Report Details">
<ion-nav-buttons side="secondary">
    <button class="button button-clear ion-ios-chatbubble" ng-click="openMessageModal()"></button>        
</ion-nav-buttons>
<ion-content class="padding">      
    content goes here
</ion-content>
</ion-view>